Device, system, and method of visual login and stochastic cryptography

ABSTRACT

Devices, systems, and methods of detecting user identity, differentiating between users of a computerized service, and detecting a possible attacker. The methods include monitoring of user-side input-unit interactions, in general and in response to an interference introduced to user-interface elements. The monitored interactions are used for detecting an attacker that utilizes a remote access channel; for detecting a malicious automatic script, as well as malicious code injection; to identify a particular hardware assembly; to perform user segmentation or user characterization; to enable a visual login process with implicit two-factor authentication; to enable stochastic cryptography; and to detect that multiple users are utilizing the same subscription account.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority and benefit from U.S. provisionalpatent application No. 61/843,915, titled “System, Device, and Method ofDetecting Identity of a User of an Electronic Device”, filed on Jul. 9,2013, which is hereby incorporated by reference in its entirety.

This application is a Continuation-in-Part (CIP) of U.S. patentapplication Ser. No. 13/922,271, filed on Jun. 20, 2013, which is herebyincorporated by reference in its entirety.

This application is a Continuation-in-Part (CIP) of U.S. patentapplication Ser. No. 13/877,676, filed on Apr. 4, 2013; which was aNational Phase of PCT International Application number PCT/IL11/00907,filed on Nov. 29, 2011; which claimed priority and benefit from U.S.provisional patent application No. 61/417,479, filed on Nov. 29, 2010;all of which are hereby incorporated by reference in their entirety.

This application is a Continuation-in-Part (CIP) of U.S. patentapplication Ser. No. 14/320,653, filed on Jul. 1, 2014, titled “Device,system, and method of detecting user identity based on motor-controlloop model”, which is hereby incorporated by reference in its entirety.

This application is a Continuation-in-Part (CIP) of U.S. patentapplication Ser. No. 14/320,656, filed on Jul. 1, 2014, titled “Device,system, and method detecting user identity based on inter-page andintra-page navigation patterns”, which is hereby incorporated byreference in its entirety.

FIELD

The present invention is related to the security of electronic devicesand systems.

BACKGROUND

Millions of people utilize mobile and non-mobile electronic devices,such as smartphones, tablets, laptop computers and desktop computers, inorder to perform various activities. Such activities may include, forexample, browsing the Internet, sending and receiving electronic mail(email) messages, taking photographs and videos, engaging in a videoconference or a chat session, playing games, or the like.

Some activities may be privileged, or may require authentication of theuser in order to ensure that only an authorized user engages in theactivity. For example, a user may be required to enter a username and apassword in order to access an email account, or in order to access anonline banking interface or website.

SUMMARY

The present invention may include, for example, systems, devices, andmethods for detecting identity of a user of an electronic device, fordetermining whether or not an electronic device is being used by afraudulent user, and/or for differentiating between users of acomputerized service or between users of an electronic device.

Some embodiments may include devices, systems, and methods of detectinguser identity, differentiating between users of a computerized service,and detecting a possible attacker. The methods may include, for example:monitoring of user-side input-unit interactions, in general and inresponse to an interference introduced to user-interface elements. Themonitored interactions are used for detecting an attacker that utilizesa remote access channel; for detecting a malicious automatic script, aswell as malicious code injection; to identify a particular hardwareassembly; to perform user segmentation or user characterization; toenable a visual login process with implicit two-factor authentication;to enable stochastic cryptography; and to detect that multiple users areutilizing the same subscription account.

The present invention may provide other and/or additional benefits oradvantages.

BRIEF DESCRIPTION OF THE DRAWINGS

For simplicity and clarity of illustration, elements shown in thefigures have not necessarily been drawn to scale. For example, thedimensions of some of the elements may be exaggerated relative to otherelements for clarity of presentation. Furthermore, reference numeralsmay be repeated among the figures to indicate corresponding or analogouselements or components. The figures are listed below.

FIG. 1 is a scatter-graph demonstrating differentiation among users, inaccordance with some demonstrative embodiments of the present invention;

FIGS. 2A-2B are schematic block-diagram illustrations of a system, inaccordance with some demonstrative embodiments of the present invention;

FIGS. 3A-3C are schematic illustrations of a modified mouse-pointerwhich may be used for distinguishing a local (genuine) user from aremote attacker, in accordance with some demonstrative embodiments ofthe present invention; and

FIG. 4 is a schematic illustration of a confusion matrix (oruser-differentiation matrix), in accordance with some demonstrativeembodiments of the present invention.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

In the following detailed description, numerous specific details are setforth in order to provide a thorough understanding of some embodiments.However, it will be understood by persons of ordinary skill in the artthat some embodiments may be practiced without these specific details.In other instances, well-known methods, procedures, components, unitsand/or circuits have not been described in detail so as not to obscurethe discussion.

The present invention may include detection and/or prevention of RemoteAccess Trojan (RAT) attacks. For example, a RAT may include a computerprogram or malware designed to give an attacker full access to avictim's computer. The present invention may protect a computer userfrom RAT attacks, by using transparent Behavioral Biometrics methodswhich may be based on analysis of interactions through mouse, keyboardand/or touch interfaces. The system may utilize an InvisibleChallenge-Response mechanism that proactively generates larger amount ofadditional behavioral biometric data without users noticing any changeto the user experience. The RAT catcher module of the present inventionmay utilize knowledge of remote access protocols to provide tailoredmade yet robust detection and prevention techniques.

Cybercriminals use RAT to gain ultimate access to infected victimcomputer(s). Using the victim's access privileges and hardwarefingerprint, they can access and steal sensitive business and personaldata bypassing hardware detection security. Many types of AdvancedPersistent Threat (APT) attacks take advantage of RAT technology forbypassing strong authentication and are commercially available (e.g.,Poison Ivy, Dark Comet, Silent VNC, Zeus Plugin, Silent Team Viewer).These may be maliciously installed on a victim's computer usingdrive-by-download and spear-phishing tactics.

In a demonstrative RAT attack, a hacker's computer communicates with ahacker's command-and-control server; which communicates with a victim'scomputer; which communicates with a service provider (e.g., an onlinebanking service). The victim's computer sends (through the hacker'scommand-and-control server) to the hacker's computer, the screen andcursor data that the victim computer “sees” when it interacts with theservice provider; whereas, the hacker's computer sends (through thehacker's command-and-control server) to the victim's computer mousedata, keyboard data, or other input unit data, which the victim'scomputer sends further to the service provider. The victim's computersends out malicious or fraudulent interactions to the service provider,through the hardware of the victim's computer; thereby traversing anyhardware identification system.

There are multiple protocols for implementing RAT. Some are proprietaryand not published, while others are known. For instance, RFB (“remoteframe buffer”) protocol works at the frame buffer level, and thus it isapplicable to all windowing systems and applications, including X11,Windows and Macintosh. RFB is the protocol used in Virtual NetworkComputing (VNC) and its derivatives. The latter is commonly used by afraudster (e.g., Silent VNC). Another example is the Remote DesktopProtocol (RDP) developed by Microsoft, which may be used for cybercrime.Moreover, some fraudsters may utilize proprietary software such asTeamViewer for creating a silent fraud-style version or write their owntool from scratch.

In an experiment in accordance with the present invention, 255 usersentered a website designed to be similar to PayPal login screen, andentered an email address, a password, and clicked a login button. Mostusers accessed the website directly, while 60 users were requested toaccess it through a web-based remote access tool (Dell SonicWALL, andEricom AccessNow). The system of the present invention was able todetect RAT with 100% true detection rate, and with 0% false detectionrate.

Reference is made to FIG. 1, which is a scatter-graph 100 demonstratingthe differentiation that may be achieved, in accordance with somedemonstrative embodiments of the present invention. The vertical axisindicates a first user-specific feature or characteristic, measured orextracted from monitored user interaction (for example, averagecurvature of mouse movement). The horizontal axis indicates a seconduser-specific feature or characteristic, measured or extracted frommonitored user interaction (for example, mouse movement speed in one ormore directions). Other suitable user-specific traits may be extracted,estimated, and/or charted or graphed.

Samples of interactions from a local are indicated with circles; samplesof interactions from a user utilizing a first RAT mechanism (RDP throughSonicWall) are indicated with squares; samples of interactions from auser utilizing a second RAT mechanism (Ercom AccessNow) are indicatedwith triangles. The two different RAT systems operate in different(non-similar) manner; and both of them, and each one of them, isdifferent from the characteristic of a local (genuine, non-RAT) user.The present invention may thus place user characteristics (interactionfeatures) on a similar chart or graph, utilizing one-dimension,two-dimensions, or multiple dimensions; in order to distinguish betweena genuine local user, and a fraudster (human hacker, or automatic scriptor “bot”) that utilizes a RAT-based mechanism, to access the service.

Reference is made to FIGS. 2A-2B, which are schematic block-diagramillustration of a system 200 in accordance with some demonstrativeembodiments of the present invention. System 200 may comprise numerouscomponents and/or modules; due to space limitations in the drawings, thecomponents and/or modules of system 200 have been distributed over twodrawings (FIG. 2A and FIG. 2B), which may be regarded or implemented asa single combined system 200 which may comprise some or all of themodules shown in FIG. 2A and/or in FIG. 2B, as if they were showntogether within a single unified drawing.

System 200 may be implemented by using suitable hardware componentsand/or software modules, which may be co-located or may be distributedover multiple locations or multiple devices. Components and/or modulesof system 200 may interact or communicate over one or more wirelesscommunication links, wired communication links, cellular communication,client/server architecture, peer-to-peer architecture, or the like.

System 200 may comprise a user-specific feature extraction module 201,which may extract or estimate user-specific features or traits orcharacteristics, that characterize an interaction (or a set or batch ofinteractions, or a session of interactions) of a user with a service,through an input unit 299 (e.g., mouse, keyboard, stylus, touch-screen)and an output unit 298 (e.g., monitor, screen, touch-screen) that theuser utilizes for such interactions. A user interactionmonitoring/sampling module 202 may monitor all user interactions and mayrecord, capture, or otherwise sample such interactions, and/or mayotherwise collect user interaction data which may enable theuser-specific feature extraction module 201 to extract or estimateuser-specific features of the interaction. A database 203 may storerecords of users and their respective estimated user-specific featurevalues.

A comparator/matching module 204 may compare or match, between values ofuser-specific features that are extracted in a current user session (oruser interaction), and values of respective previously-captured orpreviously-extracted user-specific features (of the current user, and/orof other users, and/or of pre-defined sets of values that correspond toknown automated scripts or “bots” or RAT mechanism). If thecomparator/matching module 204 determines that one or more features, ora set of features, that characterize the current interaction session ofthe current user, does not match those features as extracted in previousinteraction session(s) of that user, then, a possible-fraud signal maybe sent or transmitted to other modules of the system 200 and/or toparticular recipients. The user-specific features, whose values may becompared or matched across usage-sessions, may include, for example,curvature (or curvature radius) of mouse movement or mouse strokes;acceleration and/or speed of mouse movement in one or more directions;and/or other suitable features.

Optionally, additionally or alternatively, the comparator/matchingmodule 204 may compare the features characterizing the current sessionof the current user, to features characterizing known RAT mechanisms,known malware or “bot” mechanisms, or other pre-defined data; in orderto determine that, possibly or certainly, the current user is actually anon-genuine user and/or is accessing the service via a RAT mechanism.

In some embodiments, the output of comparator module 204 may be takeninto account in combination with other information, securityinformation, user information, meta-data, session data, risk factors, orother indicators (e.g., the IP address of the user; whether or not theuser is attempting to perform a high-risk activity such as wiretransfer; whether or not the user is attempting to perform a new type ofactivity that this user did not perform in the past at all, or did notperform in the past 1 or 3 or 6 or 12 months or other time-period; orthe like). The combined factors and data may be taken into account by auser identity determination module 205, which may determine whether ornot the current user is a fraudster or is possibly a fraudster. The useridentity determination module 205 may trigger or activate a fraudmitigation module 206 able to perform one or more fraud mitigating stepsbased on that determination; for example, by requiring the current userto respond to a challenge, to answer security question(s), to contactcustomer service by phone, to perform two-step authentication ortwo-factor authentication, or the like.

The present invention may utilize active sensing and preventing of RAT,based on examination of different remote access protocols, operationsystems, hardware and viruses in a controlled environment and underdifferent network configurations. RAT detection may be achieved orimproved by using a perturbation generator module 207, able to introduceactive perturbation(s) on the client computer, which may not affect thelocal (genuine) user but may help to detect or even prevent remote userfunctionality or a RAT-based user, thereby making the RAT-catchingsystem of the present invention more robust and efficient, allowing toboth detect and prevent RAT in various protocols and scenarios with zeroor near-zero false rejection rates.

Some embodiments may utilize a mouse-pointer hiding module 230, able tocause the mouse-pointer to “disappear” or vanish or be non-visible or beless visible on a screen or monitor of a remote user (who utilizes a RATmechanism), while the mouse-pointer is fully-visible or at leastpartially-visible (or continuously visible) on the victim's computerscreen; or vice versa. In some embodiments, the mouse-pointer hidingmodule 230 may operate to avoid showing a mouse-pointer on the victim'scomputer screen (e.g., by showing a white-on-white arrow, or atransparent arrow), while the victim's computer continues to transmit ortransfer mouse-pointer coordinates to the remote attacker's computerwhich presents (on the screen of the attacker's computer) a visiblemouse-pointer based on the transmitted pointer coordinates; and in suchcase, the system may differentiate or distinguish between users, sincefor example, the remote attacker may continue to operate regularly withregular mouse movements (as he is able to see the mouse-pointer on theattacker's computer screen), whereas a genuine local user may not seelocally the mouse-pointer and may perform reactive operations (e.g., maymove his mouse in a circle, or may move his mouse sidewaysback-and-forth, or up-and-down; or may press the Escape key, or mayperform hectic mouse movements).

In another implementation, a mouse-pointer displacement module 231 mayoperate to cause displacement of the mouse-pointer (e.g., an arrow orother cursor or pointer), visible on the remote attacker's screen,relative to the mouse-pointer that is visible on the victim's screen.For example, the mouse-pointer displacement module 231 may replace themouse-pointer in the victim's computer with a large transparent image(e.g., square or rectangle; for example, 150×150 pixels, or 200×200pixels), having a smaller arrow (e.g., 10 or 15 or 20 pixels long) at anedge or corner or side-region of the image. The remote attacker'scomputer may present the mouse-pointer according to the coordinates ofthe center of the image (the center of the square or rectangle); and asa result, a click or double-click performed by the remote attacker,based on the location of the center of the large image, would actuallybe displaced or deviated relative to the location of the arrow that isvisible on the victim's computer. The system may utilize this deviationor displacement of the mouse-pointer, to distinguish among users; forexample, the remote attacker (whose computer shows an arrow based ontransmitted cursor coordinates) would click “correctly” on buttons orfields or items; whereas a genuine local user, who sees a “displaced”arrow shown in a corner or an edge of a greater transparent rectangle,would click “incorrectly” on white spaces or in proximity to GUIelements (e.g., near buttons, near text-fields, near radio-buttons, nearcheckboxes) but not inside them.

Reference is made to FIGS. 3A-3C, which are schematic illustrations of amodified mouse-pointer which may be used for distinguishing a local(genuine) user from a remote attacker, in accordance with somedemonstrative embodiments of the present invention.

As shown in FIG. 3A, the mouse-pointer of a computing device (whichbelongs to the genuine user, the local user) may be modified or changedor replaced with a rectangular or square-shaped image 301, having a“fake” arrow pointer 303 in its upper-left corner. The center 302 of theimage 301 is denoted with “x” in FIGS. 3A-3C, in order to facilitate thediscussion herein, but no “x” and no other indication is actually shownat or near the center 302 of the image 301. Similarly, the frame ofimage 301 is shown in FIGS. 3A-3C for explanatory purposes, but is notshown on the screen in the actual implementation. The result ofreplacing the mouse-pointer with image 301 is, that a “fake” arrow 303is shown at the corner, away from the “real” center 302 which is emptyand does not show any pointer.

FIG. 3B demonstrates how a remote attacker is able to correctly and/orrapidly click on a “submit” button 305. The remote attacker's computerreceives from the victim's computer the coordinates of the center 302,and the remote attacker's computer shows to the attacker (on his remotecomputer) a mouse-pointer at that center 302; the remote attacker bringsthat mouse-pointer into the “submit” button 305, and is able tocorrectly click within the submit button.

In contrast, FIG. 3C demonstrates how the local genuine user is not ableto correctly (or rapidly) click within the “submit” button 305. Thelocal user does not see the mouse-pointer at the center 302 of the image301; rather, the local user sees only the “fake” arrow 303 at the cornerof image 301. Therefore, the local user may move his mouse to bring that“fake” arrow 303 into the “submit” button 305, and may click on themouse button there. However, such mouse-click will not actuate the“submit” button 305, because only the “fake” arrow is within theboundaries of the “submit” button 305, whereas the “real” coordinates ofthe center 302 are deviated away, externally to the “submit” button 305.Accordingly, the local user may be clicking (sometimes repeatedly,several times in a row) within a white area, or within area that is notoccupied by GUI elements. This may enable system 200 to differentiatebetween the local genuine user and the remote attacker.

Referring again to FIGS. 2A-2B, in another implementation, a RAT latencyestimator 232 may be used in order estimate whether a current user is alocal (genuine) user or a remote (fraudulent, RAT-based) user, byintroducing or generating or injecting an aberration or perturbation orinterference or anomaly (e.g., a UI-based or GUI-based aberration orperturbation or interference or anomaly), and measuring or monitoringthe response time that elapses until the user reacts to suchperturbation. For example, the perturbation generator module 207 maycause the mouse-pointer to entirely disappear, on both the victim'scomputer screen and the remote attacker's computer screen, via asuitable command or operating system procedure or function or script; alocal (genuine) user may immediately react to such disappearance of amouse-pointer (or cursor), via one or more suitable reactions (e.g., maymove his mouse in a circle, or may move his mouse sidewaysback-and-forth, or up-and-down; or may press the Escape key, or mayperform hectic mouse movements); whereas a remote attacker or aRAT-based attacker may suffer from some degree of latency incommunication, due to his being remote, and thus the remote attackerwould react to such disappearance later or significantly later than alocal (genuine) user would react. The system may thus utilize suchinjected GUI-based (or other types of user experience) interferences, asa trigger for measuring the latency in user response or the latency inuser reaction; a greater latency (e.g., relative to previousmeasurements, or relative to a threshold value) may indicate that theuser is a remote attacker or a RAT-based attacker; while a shorterlatency (e.g., relative to previous measurements, or relative to athreshold value) may indicate that the user is a local (genuine) userand not a remote attacker.

Optionally, the system may create user-specific profiles which maycomprise cognitive and/or behavioral user-specific traits, based onaberrations or discrepancies that may be based on (or related to)cognitive bias, in order to identify possible identity theft, fraudster,“man in the browser” attacker, and/or non-human (“bot”) moduleimpersonating a human user. Such user-specific traits may be extractedby utilizing, for example, priming, Stroop effect, bias of free choice,false frame effect, or the like. For example, a cognitive bias estimator233 may be used to trigger, and measure or estimate, cognitive bias oruser(s) for purposes of differentiating between a genuine or local user,versus a remote user or remote attacker or RAT-based used. In ademonstrative example, the perturbation generator module 207 mayintroduce a GUI-based perturbation only at a log-in screen of a serviceor application or website; for example, causing the mouse-pointer tomove in a certain deviated manner relative to the hand-movement of theuser. A genuine (local) user may have cognitive bias, and may operatehis local mouse device in a way that “corrects” the mouse-pointerdeviation in the log-in screen. In the next or subsequent screen, theperturbation may not be maintained by the system, or may be removed bythe system; a local (genuine) user may still have some degree ofcognitive bias, and may still operate the mouse (at least for a shortperiod of time, e.g., 1 or 2 or 5 seconds) in the previous “corrective”manner that he did in the log-in screen. In contrast, some types ofremote attackers, or RAT-based attackers, may not operate prior to thelogging-in of the genuine user, or may start operating only after thegenuine user logged-in; and such remote attacker would not be aware ofany log-in screen perturbation that had occurred, and would not have anycognitive bias, and would not operate his mouse in the “corrective”manner that a biased local user would do. This may allow the cognitivebias estimator 233 to distinguish between a genuine local user and aremote attacker.

Some embodiments may identify man-in-the-browser attacks or sessionhijacking attacks, based on behavioral and/or cognitive meta-datarelated to the particular application being used, for example, differentresponse time, different hardware-related behavior, cognitive variancebetween adjacent sessions, responses to aberrations, cognitive bias, orthe like. Some embodiments may utilize biasing, hardware identification,adjacent sessions identification, and/or identification of RAT attacks.In some embodiments, the RAT identification may have an equal error rate(EER) of virtually zero percent when hundreds of users are observed.

In some embodiments, an interaction signal sampling and analysis modulemay analyze a sample of the signal of the user interaction, thefrequency of sampling, the types of noise of the sample, channelestimation, response time to aberrations, diluted mouse trajectorysamples, first order hold sampling of mouse trajectory, or otheruser-specific traits which may be extracted or analyzed when two users(human and/or non-human) generate a signal corresponding touser-interaction at different times and at different sampling rate. Forexample, sampling of mouse movement of a remote attacker's mouse, may bedifferent from sampling of mouse movement of a local (genuine) user.

In a first example, in a remote communication session the communicationprotocol attempts to reduce communication overhead, and thus may sampleless mouse-movement points or may sample the mouse movement at a lower(or reduced) frequency, relative to a local system that does not havecommunication limitations; and as a result, the mouse movement of aremote attacker, when sampled, may show a less-smooth movement or a more“noisy” or noise-affected movement, whereas sampling of a mouse movementof a local user would show a smooth or smoother movement with lessnoise; thereby allowing the interaction signal sampling and analysismodule to differentiate between a remote attacker and a local user.

In a second example, the remote communication session (of the RAT-basedattacker) may suffer from its own limitations, constraints, latency, orits own noises or patterns of noise; which may affect the mouse-movementsampling, and may allow differentiation between the remote attacker anda local user based on such communication noises of the remote accessprotocol.

In both examples, additionally or alternatively, such “noises” in theremote access protocol may affect the latency (or timing) of userreaction to the injected perturbation, and/or may affect the pattern orother characteristics of the use reaction (e.g., the shape of the mousemovement itself). In some embodiments, optionally, a remote-accessburdening module 234 may be used by system 200 in order to intentionallyburden or overload the victim's computer resources and/or to burden oroverload the remote access protocol (for example, by requiring thevictim's computer to upload and/or download large amounts of data from aserver controlled by the service being protected, thereby leavingnarrower bandwidth and increased latency for the attacker's remoteaccess communication channel); and thereby increasing the effects ofsuch noises due to overloaded communication protocol, or making suchcommunication noise more significant and more observable, and enablingsystem 200 to detect the remote attacker more rapidly or in a morecertain manner.

The user-specific signal characteristics may be stored in the database203, and may be used subsequently by comparator/matching module 204 inorder to compare or match between current-characteristics andpreviously-estimated characteristics, thereby enabling a decisionwhether or not the current user is genuine or fraudulent.

Some embodiments may identify man-in-the-browser (MITB) attacks orsession hijacking attacks, based on user-interaction data, injection ofaberrations, analysis of user reaction, and extraction of parametersthat may indicate fraud. In a demonstrative example, a remote attackermay utilize a “Trojan” malware module that is installed on the computingdevice of the genuine user, when the genuine user is logged-in to therelevant service (e.g., online interface of a bank account). Theattacker may thus enter into the account of the genuine user, and mayoperate therein. Such attack may include, for example, two sessions thattake place in parallel or in sequence; operation of the attacker from aremote computer; utilization by the attacker of hardware which may bedifferent from the hardware of the victim's device; and/or utilizationof an automatic script which may operate on the bank account (from aremote server, or directly from the victim's device). The terms “RAT” or“Remote Access Trojan” are used herein for demonstrative purposes; andmay include other types of Remote Access (RA), remote access via amalware or virus or malicious code, or other types of unauthorized orillegitimate or illegal remote access.

In some RAT attacks, a malware module is installed in a victim's device,and sends or transmits data to a remote computer of the attacker, thedata including mouse data as well as screen-shots. Often, to allow asmaller upload of data from the victim to the attacker, images arecompressed, or are skipped (e.g., the mouse pointer may be uploaded tothe attacker, whereas an underlying background image may be sometimesskipped). The system 200 may utilize an aberration generator 209 togenerate one or more aberration(s) that will cause a situation in whichthe attacker and the victim do not see a visually identical screen, andtherefore their reaction would be different and may allow the system toidentify the attacker. For example, the aberration generator 209 maygenerate or inject an aberration or interference, which causes thevictim's computer and the remote attacker's computer to shownon-identical screens, due to timing difference, latency, bandwidth orthroughput limitations (of the connection between the attacker and thevictim), due to utilization of different hardware (e.g., differentscreen sizes or screen resolution) by the attacker and victim, or thelike. For example, the mouse pointer may be moved or relocated, to be atdifferent locations; such as, to be in a first location at the victim'sscreen, while being in a second location at an attacker's screen.

Additionally or alternatively, the upload or transmission channel (tothe attacker's device) may be sabotaged, by a channel overloading module210, such as by creating an overload of data that needs to be uploadedor downloaded or exchanged or transmitted between the attacker and thevictim (or vice versa); or by causing a significant delay or latency forthe attacker, for example, by sabotaging the ability to efficientlycompress image(s), e.g., by broadcasting video (for example, invisiblyto the genuine user) or rapidly-changing graphical elements orrapidly-changing content items or rapidly-updating content items. In ademonstrative implementation, data which should not typically bedisplayed as a video (e.g., text, static image), may be presented as avideo or a continuous video clip, to overload a transmission channelwhich an attacker may utilize for the RAT mechanism. The system 200 mayotherwise cause aberrations or intentional discrepancies that mayoverload the communication channel between the victim device and theattacker device, thereby causing the communication channel to operate ina bursting manner and thus make the attack identifiable.

Optionally, the system may cause the victim's computer to perform anupload at a particular frequency, which may then be identified in thesignal of the mouse events of the remote attacker. For example, system200 may comprise a sampling frequency modifier module 235 which mayperform one or more operations which may cause, directly or indirectly,a modification (e.g., a decrease or reduction) in the frequency of thesampling of the input unit interaction of a remote attacker. In ademonstrative example, system 200 may comprise an animation/videoburdening module which may present on the victim's computer screen, oneor more animation clips and/or video clips of generally static content,such that the victim may not even notice that they are animated orvideos; for example, rapid animation or video which switches between two(or more) very similar shades of a particular color that arenon-distinguishable to the eye of a typical user. The remote accessprotocol that is used in the RAT attack needs to transmit the screencontent of the victim's computer to the remote attacker's computer; andtherefore, the excessive animation/video may burden or overload theremote access communication channel, and may cause a modification of thefrequency of the sampling of the interactions of the attacker; and thefrequency in which the animation (or video clip) is being animated mayaffect in a particular manner the frequency of the transmittal ofpackets from the victim's computer to the remote attacker's computerand/or may affect the sampled signal that represents the interactions ofthe remote attacker; thereby allowing system 200 to more rapidly or morecertainly detect that a remote attacker is interacting with the service.

Some embodiments may extract time-based or time-related parameters whichmay be user-specific and may be used as user-specific traits for useridentification purposes. For example, aberrations or challenges may begenerated and injected into an interaction of a user with a service orapplication or website, which may require a response or reaction fromthe user (in a visible or conscious manner, or in a non-visible orun-conscious manner, from the user's point of view). An aberrationreaction monitoring module 211 may monitor and determine the reaction ofthe user to introduced aberrations, as well as characteristics of suchreaction; for example, was the reaction correct or incorrect, the timingor the latency of the reaction, or the like. Time-based parameters maybe extracted, for example, the time period that it takes the user torecognize or discover the aberration and/or to respond to it (or resolveit), the time period that it takes the user to adapt his behavior (e.g.,his general mouse movement) to a continuous aberration (e.g., adaptationtime, training time), learning curve of the user regarding theaberration (frequency or rate of corrections; magnitude of corrections),or the like. A remote attacker typically has a latency or time-delay,with regard to appearance of the aberration or challenge, as well asdifferent time-based parameters for responding to the aberration orchallenge; and this may allow the system to distinguish or discriminatebetween the genuine user and a remote attacker.

Some embodiments may analyze a sampling signal of the user interaction,for example, sampling frequency (mouse-related, keyboard-related,touch-screen related), types of sampling noises, channel estimates,response time to aberrations, diluted mouse trajectory samples, firstorder hold sampling of mouse trajectory, or other parameters which maybe different from (or may be affected by) parallel operation of twousers (e.g., a genuine user and a remote attacker) that generateinteraction signals at different times and with different samplingfrequencies. Optionally, such features may be extracted in order toestimate or determine the type of hardware utilized by a user, andthereby assist in distinguishing between a local user versus a remoteattacker. In a demonstrative example, system 200 may comprise a hardwareidentification module 236 able to identify hardware utilized by the userand/or able to distinguish between hardware utilized by a remoteattacker or a local (genuine) user. For example, each set of hardwarecomponents of a computing device, may sample the mouse events at adifferent frequency and/or with dependence on the available resources(or the overload) of the computer being used. A machine-learning processmay be performed in order to allow the hardware identification module236 to learn the characteristics of the sampling of the mouse events (orkeyboard events) of the genuine user, given an average level of computerresources burdening (or availability), which may be known or unknown. Inmany cases, the remote attacker may utilize a computer or computingdevice having hardware specifications and/or resources availability thatmay be different from those of the victim's computer; and therefore, thesampling of the remote attacker's mouse interactions (or keyboardinteractions) may be different from that of the local victim's; therebyallowing the hardware identification module 236 to determine that acurrent user utilizes a mouse (or keyboard) that are different fromthose that the genuine user had used in previous usage sessions,triggering a possible fraud alert.

In some embodiments, a remote attacker may utilize a remote device(having a remote display unit and a remote mouse and keyboard), whichmay translate into a relatively low sampling frequency for the userinteraction of such remote attacker. Optionally, an aliasing injectormodule 212 may inject or introduce aliasing operations, which may not bevisible or noticeable or significant to a local (genuine) user, but maysignificantly burden the interaction of a remote attacker. For example,a mouse pointer may be alternately hidden (e.g., at a frequency of 50Hz), thereby causing the mouse pointer to be visible only to a localuser but not to a remote attacker (or vice versa, depending on the exactconfiguration of such aberration); and the user's response may allow toidentify whether the user is a genuine local user or a remote attacker.

In some embodiments, an adjacent session detection module 213 mayidentify adjacent usage sessions of the attacker and the victim. Forexample, the system may compare between sessions having a relativelyshort time interval between them (e.g., five seconds apart, or oneminute apart); the system may compare the user interaction parameters ofthose two sessions, between themselves and/or relative to one or morehistoric profile(s) or previously-monitored interaction sessions of thatuser. In some embodiments, the system may analyze the later of the twosessions against the interaction parameters of the earlier of the twosessions, rather than against the historic or general interactionprofile of the user. Optionally, the system may generate an ad-hocprofile or temporary profile, per usage session, which may be stored andutilized for a short period of time (e.g., 30 or 60 minutes);optionally, an ad-hoc profile or temporary profile may not necessarilybe merged or fused into the general profile of the user; but rather, maybe kept or utilized temporarily, while evaluating whether or not thecurrent user is indeed the genuine user or an attacker; and only if thesystem determines that the current user is genuine, then, his long-termprofile may be updated in view of his interactions in the currentsession.

Some embodiments may identify a fraudulent usage session by training theuser to a particular behavior and testing for such behavior; forexample, by launching aberrations that cause the user to change its modeof interaction within the next few seconds or minutes and while theaberration is still carried on. For example, the system may change therelation between the physical movement of the mouse and the virtual oron-screen cursor or pointer during the log-in process, and then makeanother modification subsequent to the log-in process. Similarly, thesystem may modify the delay time or delay interval between thepressing-down of a key on the keyboard, and the appearance of thesuitable character on the screen. The system may generate other, small,aberrations in proximity to a button or link that needs to be clicked orselected, thereby requiring the user to aim the mouse more accurately;or in a touch-screen device, introducing an artificial delay betweentouching an on-screen key until character appears on the screen, therebycausing the user to prolong or extend the pressing time or touchingtime. In some embodiments, one of the two sessions may be injected withsuch aberrations, whereas another of the two sessions (e.g., thelater-starting session) may not be injected with such aberrations; andsampling and analysis of input unit events may enable the system todistinguish between a local (genuine) user and a remote attacker.

Some embodiments may utilize a priming messages module 237, such that amessage is briefly or instantaneously shown or is flashed on the screenfor a very short time in order to convince the user, sub-consciously, touse a first button or interface element instead of a second one. Thesystem may identify a remote attacker or “bot” or malware due to theirignoring of such priming messages, which may not be transferred from thevictim's computer to the remote attacker's computer due to limitationsof the remote-access protocol or communication channel; or the systemmay identify a remote attacker since such priming messages maydifferently affect the interactions of different users (e.g., thegenuine user may ignore such priming messages, whereas the remoteattacker may obey them; or vice versa).

Some embodiments may detect that a mobile computing device (e.g., asmartphone, a tablet) is being controlled (or was controlled) via aremote access channel (e.g., by a remote attacker who utilizes anon-mobile computing platform, such as a desktop computer or a laptopcomputer). Some embodiments may detect that a mobile computing devicethat has a touch-screen and an accelerometer (e.g., a smartphone, atablet) is being controlled (or was controlled) via a remote accesschannel by a remote attacker who utilizes a computing platform thatlacks an accelerometer (such as a desktop computer or a laptopcomputer). Some embodiments may detect other scenarios or attacks, inwhich an attacker utilizes a desktop or laptop computer, in order toremotely access a mobile computing device (e.g., smartphone or tablet).

For example, touch-screen movements and/or gestures and/or taps may bemonitored, captured and/or sampled; and may be compared or matchedagainst accelerometer(s) data for the same time-period (or for a timeperiod or time-slot which is at least partially overlapping). The systemmay detect that the touch-screen event sampling indicates that the userof the mobile device has manually performed gestures on thetouch-screen; whereas, at the same time, accelerometer data from themobile computing device is absent, or is null, or indicates noacceleration and no deceleration. Such mismatch or anomaly may indicatethat the mobile computing device (e.g., smartphone or tablet) is or wasactually being controlled remotely, by an attacker who utilizes a remoteaccess channel, which enabled the attacker to emulate or simulate“touch-screen gestures” (taps, movements) through the attacker's inputunit (e.g., mouse, touch-pad), but did not enable the attacker to affectthe accelerometer data that the mobile computing device produces. Someimplementations may thus detect that a mobile computing device appearsto be performing manual gestures, while the device itself is notphysically moving or shaking (even minimally), or while the deviceitself is at a complete rest; thereby indicating that possibly a remoteaccess attack is or was performed.

System 200 may further comprise an Automatic Script Detector (ASD)module 241, which may be a component or module able to detect anautomatic script (or malware, or virus, or Trojan, or “bot”, ormalicious automated code or program), which may attempt to control auser account (or a subscriber account, or an online account of a genuineuser), in an un-authorized or illegal or fraudulent manner. In someembodiments, the ASD 241 may utilize one or more of the functionsdescribed above, in order to detect such automatic script, or in orderto distinguish or differentiate between a human user (e.g., the genuineor legitimate or authorized human user) and a “bot” or automated script.It is clarified that ASD module 241 may detect, for example, that amalicious or unauthorized automatic script or code is running or is“interacting” artificially or automatically with a computerized service,or is “impersonating” a human user. Naturally, some or most computingdevices may run authorized scripts, such as Operating System, drivers,anti-virus programs, authorized background tasks (e.g., backups); andthe ASD module 241 is not aimed at detecting such authorized processes,but rather, aimed at detecting unauthorized and/or unknown and/ormalicious scripts or code or programs.

Some embodiments may detect an automatic script which may operate as aman-in-the-browser attack (or in a man-in-the-middle attack), and whichmay modify some or all of the data items that are sent from the victim'scomputing device to a web-server or application-server; for example,modifying a recipient bank account data, when the genuine user instructshis bank to perform a wire transfer. The system may identify such scriptor attack, by comparing between the original data that the genuine userhad inputted and instructed to send out, to the (modified) data that wasactually received at the bank's server. In a demonstrative embodiment,the system may detect that the genuine user had inputted six keystrokeswhen he types the recipient's name, whereas the recipient's name asactually received at the bank server has other number of characters (notsix characters). Some embodiments may further examine patterns of theinputting method, if the number of characters is identical, in order todetect a possible fraud.

In some implementations, the ASD module 241 may comprise or may utilizean interaction data correlator 242, able to correlate or match orcompare between: (a) data indicating that a transaction was commanded orordered or requested from the user's side, and (b) data indicatinguser-interface interactions (e.g., mouse-clicks, mouse gestures, mousemovements, keyboard keystrokes, touch-pad events, mouse events, keyboardevents, other input-unit events). For example, the ASD module 241 may beconnected to, or associated with, an online banking application orweb-site or service; and may monitor interactions of the user with thatservice. The ASD module 241 may detect that the online banking servicereports that the user commands to perform a wire transfer (e.g., withoutnecessarily receiving from the banking service a copy of the actualdata, such as, without receiving the data of the beneficiary name, thebeneficiary account number, the amount of wire transfer, or the like).Upon such report or trigger from the online banking service, the ASDmodule 241 may check whether or not any input-unit interactions werereceived from the user's device, for example, in a particular recenttime-period (e.g., in the most-recent 1 or 2 or 5 or 10 minutes). Forexample, the interaction data correlator 242 may detect that even thougha wire transfer was commanded or requested from the user's side, the GUIor UI interactions or the input-unit interactions do not show any inputor any gestures or dynamics in the past 5 minutes; and therefore, theinteraction data correlator 242 may determine that the commanded wiretransfer was not entered by a human user, but rather, might possiblyhave been submitted automatically by an automated script or a “bot”program which automatically and electronically submits form data withoutmoving the mouse and/or without typing on the keyboard. The interactiondata correlator 242 may thus trigger an alarm or alert notification forpossible fraud.

In another implementation, the interaction data correlator 242 mayfurther correlate or compare or match, between (a) meta-data about theinput-unit interactions that were actually performed, and (b) meta-dataabout the data that the banking service has received as part of thebanking command. In a demonstrative example, an automated script maymanipulate or modify or replace data that a human (genuine) user typed,and may submit the modified or fraudulent data to the banking service inlieu of the correct data that the human user has entered manually. Forexample, the human user may use the keyboard to enter a firstbeneficiary name of “John Smith” (having 10 characters, including theSpace), and having an account number of “12345678” (having 8 digits),and having a beneficiary city address of “Miami” (five characters);whereas, the automated script may manipulate or modify or replace theuser-entered data, after the user typed it but prior to its electronicsubmission to the banking service's server, to a second beneficiary name(such as “David Malcolm”, having 13 characters), having an accountnumber of “1234567” (having 7 digits), residing in a city of “Moscow”(having 6 letters). The interaction data correlator 242 need not receivefrom the banking service the actual data of the wire transfer details;rather, the interaction data correlator 242 may receive only themeta-data describing the data, such as, that the wire transfer requestis to a beneficiary name having 13 characters, to a bank account having7 digits, and to a city having 6 characters. The interaction datacorrelator 242 may inspect the recently-captured user interactions(e.g., keystrokes, mouse dynamics, mouse events, keyboard events, otherinput-unit events) and may determine that the command meta-data does notmatch the user-interactions (or the user interaction meta-data);because, the beneficiary name in the wire request has 13 characters, butthe interaction data correlator 242 does not observe a series of 13characters entered within a short period of time (e.g., within 4seconds) as a separate batch from other data; or because the interactiondata correlator 242 observes an initial batch of 10 characters enteredrather than 13 characters. The interaction data correlator 242 may thusdetermine or deduce that an automatic script or “bot” has possiblyintervened to manipulate, replace or modify the data that the userentered manually, with fraudulent data whose meta-data does not matchthe meta-data of the user interactions; and the interaction datacorrelator 242 may proceed to generate an alarm or alert notification ofpossible fraud.

In some implementations, the interaction data correlator 242 mayoptionally monitor and analyze the grouping of characters into “fields”or “batches”, and not only the total number of keystrokes or characters;by using a grouping analyzer 243. For example, the genuine user mayenter “John Green” and also “Boston”, totaling 16 characters; and theautomated script may fraudulently replace them with “David Green” and“Miami”, which are also totaling 16 characters. The interaction datacorrelator 242 may perform grouping into batches, and may notice thatthe manual input that was received corresponds to: a first batch of 10characters, followed after ten seconds by a second batch of 6characters; whereas, the data in the wire command (as manipulated by theautomated scripts) corresponds to batches of 11+5 characters, and thusdoes not match the grouping or batching of the manual user interactions;thereby triggering an alert notification for possible fraud.

In some implementations, the interaction data correlator 242 may utilizea hash/checksum module 244, in order to compare or match or correlatebetween hash values and/or checksum values of (a) data that the bankingservice indicates as being received from the user, and (b) datareflecting the monitoring of user interactions through the inputunit(s); and without necessarily receiving from the banking service theactual data of the banking order. For example, the banking service mayindicate to the interaction data correlator 242 that a wire transfercommand has been received, with a beneficiary name having ten charactersand having a checksum of a hash-value of “54321”. The interaction datacorrelator 242, in conjunction with the checksum module 244, may checkwhether any recently-entered group or batch of ten characters, ascaptured from monitored user interactions, has a checksum or hash-valueof “54321”; and may generate a possible fraud alert if such match is notdetected.

In some implementations, a keystrokes spacing module 245 may be used todetect anomalies or fraud based on expected or observed gaps inkeystroke entry. For example, an automated script may input data byemulating a fixed-rate typist which types at a generally fixed rate(e.g., one character every second; or one character everyhalf-a-second); whereas, a human user may not have a fixed time-gapamong keystrokes. Furthermore, some automated scripts may attempt toinsert random or pseudo-random time-gaps between emulated keystrokes, tocreate an impression of a human user typing (rather than an automatedscript). However, a human user typically enters certain groups ofkeystrokes more rapidly and/or with reduced time-gaps (or with almost notime gaps), and this may be used by the keystrokes spacing module 245 todifferentiate between (i) a human user, and (ii) an automated scriptwhich enters characters in a synthetic or artificial manner“impregnated” or augmented with pseudo-random time-gaps. For example, afirst user may type the common suffix “tion” (as in “question”,“motion”), rapidly and with very little time-gaps among characters; ormay type the common prefix “re” (as in “recall”, “remove”) or the commonsequence “the” (as in “the”, “there”, “them”) more rapidly or with verylittle time-gaps among characters; whereas an automated script may entercharacters with fixed or pseudo-random time-gaps or intervals that donot correspond to the user-specific spacing or no-spacing while typingmanually certain keystroke sequences. These properties may be monitoredand analyzed by the keystrokes spacing module 245; and may be utilizedin order to distinguish or differentiate between (a) a human user, and(b) an automated script; and/or may be utilized in order to distinguishor differentiate between two human users (e.g., a genuine or legitimateuser, versus a fraudster or imposter or attacker or hacker).

System 200 may further comprise a Code Injection detector 246, able todetect a fraudulent or possibly-fraudulent situation in which a code orprogram or script is injected or added to a website or application orservice; for example, able to detect an HTML injection attack. In ademonstrative example, a malware or virus or Trojan is maliciouslyinstalled on a computing device or electronic device of a genuine user;who then access a particular service or website or application (e.g.,banking, electronic commerce). The server of the accessed service (e.g.,banking web-server) sends to the user's device an HTML page, whichrequires the user to enter a username and a password. The malware on theuser's computer intercepts the received HTML code prior to its renderingin the browser; and the malware then modifies, manipulates, replacesand/or augments the HTML code. For example, the malware may inject oradd to the original HTML code (that was received from the bank'sweb-server) additional HTML code (“injected code”), which also requiresthe user to enter her social security number, and/or to answer asecurity question (e.g., place of birth), as part of a fraudulent,modified, log-in page which is then rendered and displayed to the userby the web-browser. The malware may then capture the additional datathat the user enters and/or submits, while transmitting back to theweb-server only the data for the originally-required fields (theusername and the password) and not the augmented (fraudulent) fields.

The code injection detector 246 may capture such code injection, forexample, by monitoring and analyzing the data or meta-data related touser interactions with input unit(s) (e.g., keystrokes, mouse clicks,mouse gestures, mouse events, touch-pad events).

In a first example, the code injection detector 246 may receive from thebank web-server an indication that a form was sent to the user's devicefor filling and submitting by the user, and that the form (as sent fromthe web-server) contains two fields to be filled-out. The code injectiondetector 246 may then detect that the monitored user interactionsindicate clearly that the user has filled-out three fields rather thantwo fields; for example, because the user has entered a sequence of 10characters (possibly his username), then pressed Tab to move to a secondfield, then entered a sequence of 12 characters (possibly his password),then pressed Tab again to move to a third field, then entered a sequenceof 9 characters (possibly his social security number, or any other thirddata-item other than the two that the bank web-server requested to befilled-out). The code injection detector 246 may thus determine thatpossibly a code injection attack is being carried out by a malwarecomponent; since the web-server of the service indicates that two fieldshave been requested to be filled-out, whereas the actual monitored userinteractions indicate that three (or more) fields have been filled-outmanually by the user.

In a second example, the code injection detector 246 may utilize data ormeta-data about the length of field(s) that are expected, compared withactual number of characters typed. For example, the bank web-server mayindicate to the code injection detector 246, that two fields areexpected to be filled-out; a username field which is limited to 16characters, and a password field that is limited to 20 characters. Thecode injection detector 246 may observe the actually-typed oractually-performed manual interactions, and may detect that the user hastyped a string with a length of 45 characters; thereby indicating thatpossibly a third field (or additional fields) have been fraudulently“injected” into the HTML code by a malware and have fraudulently inducedthe user to type excessive number of characters than expected.

System 200 may further comprise a hardware assembly detector 247 able todetermine one or more properties of the hardware components that areactually used by a user of a computing device, based on analysis of userinteractions (e.g., keystrokes, mouse gestures, mouse events, mouseclicks, touch-pad events, and/or other input-unit events orinteractions).

In a first example, a stroke evaluator module 248 (which may also bereferred to herein as a long-stroke evaluator module) may be used inorder to evaluate or analyze long strokes that the user performs. Forexample, the long-stroke evaluator module 248 may monitor and mayevaluate all the strokes (or gestures) in which the user moves theon-screen pointer (e.g., mouse-pointer, arrow-shaped pointer, cursor, orthe like); or the top K percent (e.g., top 5 percent or top 10 percent)of the strokes when ordered based on their length in descending order.The long-stroke evaluator module 248 may detect, for example, that in afirst usage session on Monday, the ten longest strokes that the userperformed have moved the pointer by 600 to 700 pixels, therebyindicating that a mouse device was used on a flat surface with a longstroke; whereas, in a second usage session on Tuesday, the ten longeststrokes that the user performed have moved the pointer by 250 to 300pixels, thereby indicating that a touch-pad was used in that usagesession. Accordingly, evaluation of the long or longest strokes of theuser, may indicate on the type of hardware that the using is utilizing;and may allow the long-stroke evaluator module 248 to distinguish ordifferentiate between a user utilizing a mouse device and a userutilizing a touch-pad.

Additionally or alternatively, the long-stroke evaluator module 248 maydetect that in the second usage session, two or three consecutivestrokes of approximately 250 pixels each, where performed consecutivelywith short time-gaps between them (e.g., less than a second, or lessthan half-a-second), indicating that the user possibly utilized atouch-pad with three consecutive horizontal strokes in order to entirelymove the on-screen pointer from the left side of the screen to the rightside of the screen.

In another example, some laptop computers may include a mini-joystick inthe center of their keyboard, also known as a “pointing stick” (e.g.,having a red rubber tip); and the utilization of such keyboard-basedpointing-stick may leave a distinguishable footprint on userinteractions; for example, may manifest such utilization by shorterstrokes that are more “bursting” in their nature, or have a greaterinitial acceleration, or have a greater ending deceleration, or thelike. The long-stroke evaluator module 248 may monitor long-strokes (orstrokes in general, not necessarily long ones) in order to detect suchtypical footprint or pattern that is indicative of a keyboard-basedpointing-stick; and may thus distinguish or differentiate between (a) auser utilizing a keyboard-based point-stick, and (b) a user utilizingother type of input unit (e.g., touch-pad, mouse).

System 200 may further comprise a sampling-based detector 249 able todifferentiate between types of input units (e.g., mouse, touch-pad,pointing-stick), and/or even between different input units of the sametypes (e.g., different types of mouse devices), based on differentsampling footprint or sampling characteristics that such input devicesmay have, individually or due to their assembly with other specifichardware components.

In a first example, monitoring the utilization of a mouse device maylead to a first type of sampling distribution or standard deviationthereof or sampling frequency thereof; which may be different from thoseobtained from monitoring the utilization of a touch-pad, or apointing-stick. Accordingly, the sampling-based detector 249 maydetermine, based on differences in the characteristics of the samplingof the input device, that a first input device is currently utilized,whereas a second input device had been utilized in a previous usagesession of the same purported user.

In a second example, mouse devices made by a first manufacturer (e.g.,Logitech) may have different sampling characteristics (e.g., frequency,distribution, standard deviation) than corresponding characteristics ofmouse devices made by a second manufacturer (e.g., HP); thereby allowingthe sampling-based detector 249 to determine that a current user isutilizing a mouse from a different manufacturer, compared to a mouseutilized in a previous usage session of that user.

In a third example, a cordless or wireless mouse may have differentsampling characteristics (e.g., frequency, distribution, standarddeviation) than corresponding characteristics of a corded mouse; therebyallowing the sampling-based detector 249 to determine that a currentuser is utilizing a wireless or cordless mouse, in contrast with acorded mouse that had been utilized in a previous usage session of thatuser (or vice versa).

In a fourth example, various models of the same type of mouse (e.g.,cordless, or corded) may have different sampling characteristics (e.g.,frequency, distribution, standard deviation), for example, due todifferent technical specifications of such different mouse devices(e.g., different physical dimensions; different resolution; being aleft-handed or right-handed or neutral mouse device; or the like);thereby allowing the sampling-based detector 249 to determine that acurrent user is utilizing a mouse model which is different from a mousemodel that had been utilized in a previous usage session of that user(or vice versa).

System 200 may further comprise a keyboard identification module 250,able to distinguish or differentiate among keyboards based on userinteractions via such keyboards. For example, rapid typing of a certainsequence of characters (e.g., “tion” or “the”) may be indicative of anEnglish keyboard being utilized; whereas, rapid typing of other sequenceof characters (e.g., “ez” which is a frequent verb suffix in French) mayindicate that a French keyboard is being utilized. Similarly, Russiankeyboard, Chinese keyboard, and other keyboard layouts may be detected,by observing and detecting particular rapid sequences of characters thatare typically entered in certain languages and not others; regardless orindependently of (and sometimes in contradiction to) the estimatedgeographical region that may be (correctly or incorrectly) deduced fromthe Internet Protocol (IP) address of the user.

For example, a genuine user may be located in the United States and mayutilize an American English keyboard layout; but a remote attackerlocated in Russia may take control over the genuine user's computer inorder to access a bank account of the genuine user. The bank web-servermay only “see” the U.S.-based IP address of the genuine user, and maythus assume or determine (incorrectly) that the service is beingaccessed by a person located in the United States; however, the keyboardidentification module 250 may observe one or more rapid key sequencesthat are indicative of a non-English/non-U.S. keyboard layout, and mayalert the banking system that a possible fraud may be occurring, eventhough the IP address of the logged-in user indicates a U.S.-based IPaddress.

In another example, different keyboard layouts may dictate, or may beindicative of, different speed or rate of typing (in general, or ofvarious words or syllables or sequences); and these parameters may bemonitored and evaluated by the keyboard identification module 250, andmay allow to distinguish or differentiate among users based on theestimated type of keyboard layout that is being utilized in a currentsession, compared to historical or past keyboard layout(s) that wereobserved in prior usage sessions.

Optionally, the hardware assembly detector 247 may utilize a resourcesburdening module 251 for the purposes of hardware assembly detection oridentification. In a demonstrative example, a web-page or application ofa service (e.g., banking service, or electronic commerce service) mayintentionally include excess code, whose purpose is to execute aresource-intensive operation or calculation (e.g., a function that findsall the prime numbers between 1 and 1,000,000); and the user's devicemay be induced into executing such code (e.g., as a client-sideJavaScript code or other client-side program) when the user is accessingthe service, in order to capture and use the footprint of such resourceburdening. For example, each time that a user logs-in to his bankingwebsite, the website may require the user's device to execute (e.g., onetime only per each log-in session) a particular resource-intensiveuser-side (e.g., browser-based) calculation, and to transmit or submitthe answer back to the server. The resources burdening module 251 mayobserve that, for example, in a first usage session the client-sidecomputation required 13 seconds; in a second usage session theclient-side computation required 13.3 seconds; in a third usage sessionthe client-side computation required 12.8 seconds; and in a current,fourth, usage session the client-side computation required only 8seconds. This may indicate that the current usage session is beingperformed by utilizing a different hardware (e.g., faster processor;increased memory) relative to the previous usage sessions, and mayindicate that a possible fraud may be taking place (e.g., by a hacker, aremote attacker, or other fraudster). Optionally, such determination ofpossible fraud may be reached, even if the IP address and/or “cookie”information indicate that the current user is the same person (or thesame device) as the user of a previous usage session.

Optionally, the keyboard identification module 250 may operate inconjunction with, or in association with, acognitive-based/non-biometric segmentation module 296, which may be ableto estimate that a user is located in a particular geographic region(e.g., continent, country) and/or that the user is fluent or knows howto write a particular language (e.g., a particular non-Englishlanguage); based on cognitive parameters which may be estimated ordetermined.

Some embodiments may perform non-biometric segmentation of users basedon cognitive behavior. For example, the system may estimate thegeographic or geo-spatial location of the user, based on an analysis ofthe key-typing by the user, which may indicate that a particularkeyboard layout (e.g., Russian keyboard layout) is being used, therebyindicating a possible geographical location (e.g., Russia or the formerSoviet Union). Some implementations may utilize a CAPTCHA challengewhich may require typing of local or region-specific or non-universalcharacters, thereby indicating a possible geographic location of theuser.

Some embodiments may utilize non-biometric segmentation of users basedon user interaction characteristics, in order to identify possibleattackers or fraudsters. The way that a user interacts with a computingdevice or website or application, may be indicative of a geographiclocation of the user, a primary language that the user masters or uses,an age or age-range of the user (e.g., relatively young age between 15to 30, versus senior citizens over 60), level of computer-proficiency orcomputer-literacy of the user, or the like. These features may beextracted for each usage session, may assist in creating a user-specificprofile, and may be used for detecting a potential attacker.

In a first example, geographic or geo-spatial features may be extracted,and may then be used for identifying a possible attacker located in Asiaand who attempts to compromise an account of a United States user orservice. In a second example, age-related features may be extracted andmay be used for identifying a possible attacker who is relatively young(under 30) and attempts to compromise an account of a senior citizen(over 60). In a third example, some younger or computer-proficient usersmay utilize certain keyboard shortcuts (for example, CTRL-V to pastetext), whereas a senior citizen may not be proficient with such keyboardshortcuts, or may not use them at all, or may even use Menu commands(e.g., Edit/Paste) to perform similar operations; thereby allowing toraise a flag or alert if an account of a senior citizen, who did notuser CTRL-V in the past, suddenly detects such usage.

Some embodiments may estimate the geographic or geo-spatial location ofa user, based on an estimate of the keyboard layout of that user byanalyzing keystroke patterns or other keystroke information; forexample, identifying strings of two or three characters, that aretypically typed quickly in first keyboard layout of a first region, butare typically types less-quickly or slowly in a second keyboard layoutof a second region. For example, the word “wet” may be typed quickly ina standard QWERTY keyboard in the United States, but may be types slowlyin a keyboard having a different layout in which the letters of the word“wet” are not adjacent. Similarly, when typing the word “read”, apartial string of “re” or “rea” is typically typed faster in some UnitedStates keyboard layouts, relative to the remaining portion of the word;and this may be different in other keyboard layouts. The system maytrack the keystroke patterns, of whole words, or of two-character orthree-character or four-character strings, and may utilize such patternsfor distinguishing between a genuine user and an attacker, or fordetermining whether a current user appears to be utilizing a keyboardhaving a different layout from the keyboard layout of a genuine user whologged-in previously or historically.

Some embodiments may similarly utilize other input-specific combinationsin order to distinguish between users, for example, utilization ofkeyboard shortcuts and/or menu commands, or utilization of a combinationof keyboard and mouse (e.g., clicking a mouse button while holding theShift key or the CTRL key); such advanced combinations may be moretypical of a younger user (e.g., age of 15 to 30), rather than a seniorcitizen user (e.g., age over 60). Similarly, the utilization of CapsLock or Num Lock or other “shifting” keys (e.g., the Windows key, or aFN function key in a laptop keyboard), may be indicative of a younger ormore-proficient user, and may be used for raising a flag or initiating afraud alert when such user attempts to handle an online account of asenior citizen.

In some embodiments, a CAPTCHA that requires to type local orregion-specific characters or language-specific characters may bedisplayed to the user, in order to further assist in distinguishingamong users or for extracting geographic data or keyboard layout data.In a demonstrative example, a web server or application server locatedin France, typically serving French users and customers, may display aCAPTCHA string of “prêt à porter”, in which two letters have accents (or“diacritical marks” or “diacritic marks”) on top of them (or under them,or near them); a user that masters the French language and/or utilizes akeyboard (hardware keyboard, or on-screen keyboard) having a Frenchlayout would probably type correctly either two or one of those accentedcharacters (with their accents, or with their diacritical marks);whereas a non-French person, or a person utilizing a keyboard that doesnot have a French layout, would probably type without any accents ordiacritical marks, “pret a porter”.

System 200 may further comprise a user-age estimator 252, able toestimate an age or an age-range or age-group of a user of an electronicdevice, based on monitored interactions of the user with input unit(s)of the electronic device. Additionally or alternatively, a userexpertise estimator 253 may estimate whether a user of an electronicdevice is a novice user or an expert user; or whether the user isexperienced or non-experienced in operating electronic devices and/or inaccessing online systems.

In a first example, the typing speed on a keyboard may be monitored andanalyzed; rapid typing speed may indicate that the user is relativelyyoung (e.g., between the ages of 15 and 40, or between the ages of 18and 30), and/or may indicate that the user is an expert or experienced.In contrast, slow typing speed may indicate that the user is relativelyold (e.g., over 60 years old; over 70 years old), and/or that the useris non-experienced or novice. Optionally, threshold values (e.g.,characters-per-second) may be utilized, with regard to the user'styping, in order to estimate the user's age or age-range, or the userbeing expert or novice.

In a second example, the user-age estimator 252 may take into accountwhether or not the user utilizes advanced options for inputting data.For example, utilization of “copy/paste” operations may indicate ayounger user or an expert user; whereas, repeated typing (even ofduplicate information, such as mailing address and shipping address) andlack of using “copy/paste” operations may indicate an older user or anovice user. Similarly, utilization of various “keyboard shortcuts” in abrowser or an application, may indicate a younger user or an expertuser; whereas, lack of utilization of “keyboard shortcuts” in a browseror application may indicate an older user or a novice user.

In a third example, the general efficiency and/or speed of the user incompleting a task may be monitored and may be taken into account by theuser-age estimator 252 and/or by the user expertise estimator 253. Forexample, if it takes the user around 60 or 90 seconds to complete allthe information required for a wire transfer, then the user may beclassified as a younger user and/or an expert user. In contrast, if ittakes the user more than 6 minutes to complete all the informationrequired for a wire transfer, then the user may be classified as anolder user and/or a novice user.

Some embodiments may distinguish between an expert user and a noviceuser, or between a technology-savvy user and a common user, based ontracking and identifying operations that are typical of such type ofuser. For example, usage, or frequent usage, or rapid usage, of keyboardshortcuts or cut-and-paste operations (e.g., CTRL-C for Copy), or usingALT-TAB operations, or performing rapid operations in a short time or atrapid rate, or avoiding usage of menus, may indicate an experienced userrather than a novice user. Utilization of the Tab key for moving amongfields in a form, or utilization of the Enter (or Return) key instead ofusing a “submit” button or a “next” button, may indicate an experienceduser. The system may identify that a previous user of an account hastypically operated the account with a pattern that typically matches anovice or non-sophisticated user, whereas a current user of the accountappears to operate the account with a pattern that typically matches anadvanced or expert user; and this may cause the system to raise a flagof alert for potential fraud. Similarly, an attempt to perform a newtype or certain type of operation in the account (e.g., a wire transfer;or a money transfer to a new destination or new recipient), togetherwith usage pattern that is indicative of an expert user or sophisticateduser, may by itself be a trigger for possible fraud.

The estimations made by the user-age estimator 252 and/or by the userexpertise estimator 253 may be compared or match to user data which mayappear in a user profile, or may be received from a third party or fromthe service provider (e.g., the bank web-server); and may be used totrigger a possible fraud alert. For example, the bank web-server mayindicate to system 200 that the current user is in the age-range of 70to 80 years old; whereas the user-age estimator 252 and/or the userexpertise estimator 253 may determine, based on analysis of actualinteractions, that the current user appears to interact as if he is anexpert user or a younger user, thereby triggering a possible fraudalert.

System 200 may further comprise a user gender estimator 254, able toestimate the gender (male or female) of the user of an electronicdevice, based on analysis of monitored input-unit interactions. In ademonstrative example, most males have short fingernails or non-longfingernails; whereas some females may have long fingernails. Applicantshave realized that when a person having long fingernails types on aphysical keyboard (having physical keys), there is typically a shortertime-gap between the “key down” and the “key up” events. Someexperiments by the Applicants have shown that it may be possible todistinguish between a male user and a female user, with level ofconfidence of approximately 65 to 70 percent or even higher. The usergender estimator 254 may thus monitor the time-gaps between key typingevents, in order to estimate whether the current user is male or female.Such gender estimation may be taken into account by a fraud detectionmodule, in combination with other parameters (e.g., time-gaps inprevious usage sessions of that user in the past; the fact that asignificant majority of attackers on banking websites or electroniccommerce websites are performed by male users and not by female users),and/or in combination with other parameters or data or meta-datareceived from the service being monitored (e.g., an indication from thebank web-server about the registered gender of the logged-in user as itappears in the user's profile).

Optionally, the gender estimation (and/or other user-specificestimations as described above) may be utilized for triggering apossible fraud alert; or may be used to the contrary, to avoid raising apossible fraud alert. For example, system 200 may estimate that a firstuser at 10 AM is a novice old male, and that a second user who accessedthe same account at 10:15 AM is an expert young male; thereby indicatinga possible fraud (e.g., the second user may be an attacker), possiblytaking into account the fact that the account indicates only oneaccount-owner. In contrast, system 200 may estimate that a first user at4 PM is a novice old male, and that a second user at 4:10 PM is a noviceold female; and may take into consideration also the fact that this bankaccount is jointly-owned by a married couple of two senior citizens;thereby allowing the second access session without raising a possiblefraud alert.

In some embodiments, an advertising/content tailoring module 255 mayutilize the estimations or determinations produced by other modules ofsystem 200, in order to tailor or select user-specific advertisements orbanners or promotional content (or other type of content, such as newsarticles, videos clips, audio clips), tailored to the estimatedcharacteristics of the user. For example, the user-age estimator 252 mayestimate that the current user is in the age-range of 18 to 30 years;the user expertise estimator 253 may estimate that the current user isan expert or experienced user; and the user gender estimator 254 mayestimate that the current user is a male; and based on theseestimations, the advertising/content tailoring module 255 may select ormodify a banner ad which suits this segment of the population.Additionally or alternatively, the advertising/content tailoring module255 may take into account geographic segmentation and/or languagesegmentation, which may be based on IP address of the user and/or may bebased on analysis of monitored user interactions which may allowidentification of foreign keyboard layouts and/or foreign languages,thereby allowing the advertising/content tailoring module 255 to furthertailor the displayed promotional content based on the additionalgeographic information and/or language information.

System 200 may comprise a credentials sharing detector 256, fordetection, mitigation and/or prevention of credential sharing (e.g.,username-and-password sharing, or other cases of “friendly fraud”) amongtwo or more users, in which one user is an authorized user or “payingsubscriber” who shares his credentials (e.g., for accessing a premiumservice) with a second user (who is not a “paying subscriber”). Forexample, John may be a paying subscriber of “Netflix” or otherstreaming-content provider; or may be a paying subscriber of“NYTimes.com” (newspaper) or of “Lexis.com” (legal informationdatabase). The user John (who may be, for example, male, 20 years old,expert user) may share his log-in credentials to such premiumsubscription service, with his aunt Susan (who may be, for example,female, 60 years old, novice user). The modules of system 200 maymonitor user interactions with the service (e.g., in the log-in page,and/or in subsequent pages that the user may browse, access, orotherwise interact with), and may estimate user-specific characteristicsbased on the user's interactions with the input unit(s), therebyallowing the system to distinguish and/or differentiate between thelegitimate user (the subscriber John) and the illegitimate user whopiggy-backs on the credentials of the legitimate user in order to accessor consume premium content without separately subscribing to it.

In some embodiments, the system may detect scenarios of two users usingone computing device, in the training phase and/or testing phase. If auser's account is suspected to have multiple users, the system may useunsupervised clustering for separating between users. Afterwards, thesystem may use separate individual model for each cluster (e.g., eachestimated user). This may allow the system to build a combined model,consisted of the individual users' models. This solution may outperformbuilding one model for all users, even though it may require more dataas the number of training sessions per user may be decreased. In someembodiments, for example, a joint-account user-profile constructor 257may be used in order to utilize the estimated differentiation or thedistinguishing between two (or more) legitimate, authorized users whohave authorization to access the same account or service (e.g., twoco-owners of a joint bank account), and may construct two separateuser-profiles that reflect the biometric and/or cognitive footprints ofeach user separately (based on each user's separate interactions withthe input unit(s) and/or the system). This may enable the system 200 todifferentiate between each one of those legitimate (but separate) users,and a third user which may be an unauthorized attacker. This approachmay yield improved and/or more reliable results, relative to aconventional approach which constructs a single user profile based onall usage sessions of a certain service or account, or relative to aconventional approach that does not attempt to distinguish between twolegitimate users accessing the same account (e.g., joint account, familyaccount).

Some embodiments may identify multiple (different) users that utilizethe same device, or the same account, before or after a typical userprofile is built, or even during a training period in which the systemlearns the behavioral patterns. This may be used for detection of“friendly fraud” incidents, or identification of users foraccountability purposes, or identification of the user that utilized aparticular function in an Administrator account (e.g., optionally usedin conjunction with a requirement that certain users, or users withcertain privileges, may not share their password or credentials with anyother person); or identification of a licensee in order to detect orprevent software piracy or unauthorized usage by non-licensee user(s),for software or products that are sold or licensed on a per-user basisor a per-seat basis.

The system may readily support multiple users per device. The system mayapproach the problem in two ways: first, identify that two users sharethe account; then either build separate models for each user, or, ifsuspicious, generate an alert (e.g., to the bank). Detection of multipleusers may happen in two phases: during initial training, or afterinitial training.

During initial training: if two or more users operate the account duringthe initial silent period, in which the system learns the user behaviorand builds a model, then the system may utilize algorithms to detectthis. In case a user's account is determined to consist of multiplehumans, the system may use unsupervised clustering for separatingbetween the different users even though a robust profile was not yetbuilt. Afterwards, the system may use separate individual models foreach cluster (suspected user). This in turns allows the system to buildindividual users' models. Some embodiments may utilize 5-10 sessions peruser (not per account) to build the model. The system may check to seeif any of the users shows typical or specific fraudster behaviors; ifyes, then an alert is generated, and if not then the system may deducethat both are genuine and may build a model.

After a model is built for the main user: in such case, a second userstarts using the account. The system may alert that this is not theoriginal user, and the system (e.g., a bank's system) may act upon thisdetermination in combination with additional factors (e.g., is the newuser conducting suspicious or high-risk activities; are there severalaccount owners on record or a single owner).

For example, one option is to elevate the risk for the account, suchthat, when the new user conducts a high-risk activity (e.g., paying to anew beneficiary, or registering a new phone number to a service whichallows withdrawing cash from ATMs without a PIN), the system may treatsuch new user as a suspect user.

Another option is to conduct a manual or automated investigation bycontacting the main user, ascertaining their identity, and then askingwhether a family member may be using the same account. If yes, then thismay be reported to the system via case management, and the system mayautomatically add that new user to the account.

A third option is to assume that as long as the new user is not doinganything risky, and is not identified as a likely fraudster based ontheir overall usage patterns (e.g., the new user does not appear tooperate like expert users, as described above), then the system maydetermine that the new user is a genuine additional user. In this casethe system may automatically build a profile for the new user and assumethey are a genuine secondary user, unless follow-up activities do showsigns of fraud behavior.

The system may optionally use a profile type in which a combined modelis built for the two users (e.g., generating an account profile peraccount, rather than a user profile per user). The system may thus have,in some embodiments, a single profile for the entire account, and testit by means of cross-validation that it can be used to accept both whilerejecting others. Adding this profile to the scoring process might offersome advantages over just building two separate user models.

Detection of multiple users during the training phase may be performedby using a particular algorithm. The system needs to accept trainingsessions where there are variations between each session (which is thecase for the majority of accounts); but the system may also need to spotsessions that are most likely done by another human, although the systemhas not yet built a robust model.

Reference is made to FIG. 4, which is a schematic illustration of aconfusion matrix 400 (or user-differentiation matrix) in accordance withsome demonstrative embodiments of the invention. For demonstrativepurposes and for simplicity, confusion matrix 400 indicates only fourdifferent “shades” or fill-patterns; whereas in real-life many (e.g., 10or 20) shades or colors may be used.

Using a mobile banking simulated environment, a scenario was tested, inwhich two people operating on the same account produce data. Theconfusion matrix 400 shows how each user session compares to all othersessions. For example, when comparing the session of User 1 to itself,the result is a deep dark square (highly unlikely to be a differentuser), as in all “User-K to User-K” comparison (the diagonal darksquares); but in all other comparisons the color is lighter (highlylikely to somewhat likely to be a different user). There are some caseswhere a single user session appears like another single user session(e.g., User-3 session looks like User-5 session); in this case thesystem might “miss” the detection of the two separate users. Overalldetection rate of some embodiments may be around is 95%, at 0% falsepositive for this test.

In the demonstrative confusion matrix 400: the diagonal black squaresare the same user (no mixture), and the off-diagonal squares aremixtures of two users. Each number for both rows and columns representsa single user. The color (or shade) of each square represents a score.The diagonal differs from the non-diagonal items, which means that thesystem may identify a mix of users in a single account even during thetraining phase.

Referring again to FIGS. 2A-2B, in some embodiments, the credentialssharing detector 256 may be implemented as, or may be associated with, a“multiple-users for same account” detector 266, which may be able todetect that two (or more) different users are accessing, or areattempting to access, at different times or during overlapping orpartially-overlapping time-periods, the same computerized service, usingthe same user-account (e.g., utilizing the same credentials,username-password pair, or other same data of user authentication). Thecomputerized service may be for example, streaming video service (e.g.,Netflix, Hulu), streaming audio service, legal information database(e.g., Lexis.co), news database or website (e.g., NYTimes.com), bankaccount, a website or application which provides access to digitalcontent to registered subscribes or to paying subscribers or to premiumsubscribers, or the like.

The two (or more) users, which may be detected, identified,differentiated and/or distinguished from each other by the system, maybe, for example: (a) an authorized or genuine user, and an attacker orhacker; or, (b) a first user who is the paying subscriber that receivedor created the login credentials, and a second user (e.g., his friend orrelative) who is not the paying subscriber, and who received the logincredentials from the paying subscriber (e.g., a “friendly fraud”situation, or a password-sharing or credentials-sharing situation); or,(c) a first user who obtained the user credentials from any source (andis not the paying subscriber himself), and a second user who alsoobtained the user credentials from any source (and is not the payingsubscriber himself), such as, for example, a mother and a sister of apaying subscriber who both received the login data from the payingsubscriber. Other suitable pairs (or groups, or sets) of multiple users,may be differentiated or distinguished and “broken” or divided orseparated into the single entities that comprise them.

In a demonstrative implementation of the “multiple-users for sameaccount” detector 266, a first user “Adam” may be a paying subscriberthat created or obtained (e.g., legally, lawfully) user credentials(e.g., username and password) for a subscription-based service. Adamshared his user credentials (e.g., possibly in contradiction toterms-of-service of the subscription-based service) with a second user,“Bob”. Each one of the two users (Adam, Bob) may be able to access theservice, from the same electronic device or from separate (distinct)electronic devices, at various time-slots or time-frames which may bedistinct or may even be overlapping or partially-overlapping orsimultaneous of partially-simultaneous; by entering the same usercredentials.

The system may continuously monitor user-interface interactions and/orinput-unit interactions (e.g., performed through a mouse, a keyboard, atouchpad, or the like), of users accessing that particular computerizedservice, including (but not limited to) the interactions performed byusers (Adam and/or Bob) who used the user-credentials of Adam, as wellas interactions performed by other users of that particular computerizedservice that are not related or connected to Adam and/or Bob and wholog-in to the service using other credentials.

The system may accumulate data reflecting the interactions of dozens, orhundreds, or thousands of users who access that service; as well as datareflecting the interactions of two or more usage sessions in which Adamand/or Bob (without the system necessarily knowing yet which one ofthem) has accessed the service with Adam's credentials.

The system may analyze the interactions, or may extract propertiesand/or attributes of such interactions; for example, distribution ofinteractions per usage session, standard deviation of sampled data perusage session, average time of usage per usage session, average numberof clicks (or keystrokes) per usage session, average time-gap betweeninteractions (e.g., between keystrokes) per usage session, typicalreaction (or reactive action, or corrective action) that is performed bya user in response to a user-interface interference that is injectedinto the usage session, and/or other attributes of each usage session.In some implementation, a usage session may be defined as a time periodthat begins when a user starts accessing the particular service bystarting to enter the login credentials, and that ends upon detectingthat a pre-defined time period (e.g., one minute, five minutes, tenminutes, one hour, two hours) has elapsed since the last userinteraction was observed for that particular service.

In a demonstrative embodiment, the system may generate numerousCross-Account Pairing Scores for pairs of usage sessions. Firstly, thesystem may generate pairing scores for two usage sessions that are notfor the same subscription account, and thus, necessarily (or mostprobably), were not performed by the same (single) human user. Forexample, if the paying subscribers of the particular service are Adam,Charlie, David, Even, Frank, and so forth, then the system may generate:

(a) a first cross-account pairing score that corresponds to acombination of: (i) the interactions of the user who utilized the logincredentials for “Charlie”, and (ii) the interactions of another user whoutilized the login credentials of “David”;

(b) a second cross-account pairing score that corresponds to thecombination of: (i) the interactions of the user who utilized the logincredentials for “Charlie”, and (ii) the interactions of another user whoutilized the login credentials of “Eve”;

(c) a third cross-account pairing score that corresponds to thecombination of: (i) the interactions of the user who utilized the logincredentials for “Charlie”, and (ii) the interactions of another user whoutilized the login credentials of “Frank”;

(d) a fourth cross-account pairing score that corresponds to thecombination of: (i) the interactions of the user who utilized the logincredentials for “David”, and (ii) the interactions of another user whoutilized the login credentials of “Eve”; and so forth, with regard topairs of usage sessions that are known to be originating from pairs oftwo different users (because they originated from two different logincredentials).

Additionally, the system may generate Intra-Account Pairing Scores thatreflect the user interactions for pairs of usage sessions that are knownto be performed for the same subscription account. For example, if theuser account of “Adam” has logged-in three times (three usage sessions),then the system may generate the following pairing scores:

(a) a first intra-account pairing score for the subscription account of“Adam”, that corresponds to the combination of: (i) the interactions ofthe user who utilized the login credentials for “Adam” in the firstusage session, and (ii) the interactions of the user who utilized thelogin credentials of “Adam” in the second usage session;

(b) a second intra-account pairing score for the subscription account of“Adam”, that corresponds to the combination of: (i) the interactions ofthe user who utilized the login credentials for “Adam” in the secondusage session, and (ii) the interactions of the user who utilized thelogin credentials of “Adam” in the third usage session; and so forthwith regard to pairs of two consecutive usage sessions that wereperformed for the same subscription account, for each such subscriptionaccount.

It is noted that a “pairing score” may actually be a “grouping score”,by similarly grouping together a set of three or four or other number,which may not necessarily be two.

The system may then analyze the cross-account pairing scores, and may(separately) analyze the intra-account pairing scores, in order todetect typical patterns or significant attributes. For example, thesystem may calculate that cross-account pairing scores have a firstvalue of a particular attribute (e.g., standard deviation, or average,or the like); and that the intra-account pairing score calculated overtwo particular usage sessions from a particular (same) subscriptionaccount have a different value of that particular attribute.

The system may analyze one or more pairs of usage sessions, that areassociated with the subscription account of “Adam”, compared relativeto: (A) pairs of usage sessions of the general population of usagesessions that belong to the same subscription account; and/or, comparedrelative to: (B) pairs of usage sessions that are known to belong todifferent users (e.g., cross-account usage sessions). The system maythus determine whether a pair of usage sessions, that were performedwith the login-credentials of the subscriber “Adam”, were indeedperformed by the same single human user (e.g., if the attributes of suchpair of usage sessions, are more similar to the attributes of pairs ofintra-account usage sessions), or conversely, whether that pair of usagesessions were performed by two different users (e.g., Adam and hisfriend; or Adam and an attacker), for example, if the attributes of suchpair of usage sessions are more similar to the attributes of pairs ofcross-account usage sessions.

In a demonstrative example, the system may check whether: (a) a pair ofintra-account usage sessions that are associated with thelogin-credentials of Adam and Adam, is more similar to either: (i) pairsof intra-account usage sessions that are associated with the same logincredentials (e.g., a pair of David+David, a pair of Eve+Eve, a pair ofFrank+Frank, an average or other parameter computed over multiple suchpairs), or is more similar to: (ii) pairs of cross-account usagesessions that are associated with different login credentials (e.g., apair of David+Eve, a pair of David+Frank, a pair of Eve+Frank, anaverage or other parameter computed over multiple such pairs).

The system may thus be able to identify that a particularsubscription-account is utilized by two different human users, rather bythe same single human user; and may generate a suitable notification(e.g., a possible fraud notification; a notification to billingdepartment; a notification to cost-containment department).

The system may be able to identify that a particularsubscription-account is utilized by two different human users, rather bythe same single human user, without relying on (or without taking intoconsideration) the Internet Protocol (IP) address associated with eachusage session (or each purported user); without relying on (or withouttaking into consideration) the user-agent data associated with eachusage session (or each purported user); without relying on (or withouttaking into consideration) any “cookie” data or “cookie” file which maybe stored or used by the computerized service.

The system may be able to identify that a particularsubscription-account is utilized by two different human users, rather bythe same single human user, without necessarily building a long-termprofile (or any type of user-specific profile) for a particularsubscription account; or without having to utilize a “training period”in which the system “learns” the habits or the repeated habits ofparticular subscribers. The system may commence to detectshared-credentials or multi-users in the same subscription account,without constructing a user profile or a subscription-account profilethat spans (or that relies on) three or more usage sessions.

System 200 may utilize visible changes of the UI or GUI or the on-screenexperience, optionally utilizing gamification features (in whichfeatures or functions are presented in a manner similar to a game orpuzzle or similar online activity), in order to identify user(s) ordetect possible fraud. For example, a login process may be subject togamification by a gamification module 258, such that a user may berequired to perform game-like operations (e.g., move or drag items,handle items relative to a virtual on-screen “magnet” in a particularlocation on the screen, complete an on-screen puzzle, rotate a spindleor on-screen wheels or handles of a virtual vault), and the user'sreactions or behavior or interactions may be utilized for identificationor fraud-detection purposes.

Some embodiments of the invention may allow a unique way of two-factor(or two-step) authentication or log-in. For example, entry of usercredentials (e.g., username, and/or PIN or password or passphrase) maybe subject to gamification or may be implemented by utilizing a graphicuser interface (GUI) or on-screen interface in a way that captures orrecognizes user-specific traits through the way that the user utilizessuch interface for entering is credentials. Accordingly, the mere entryof credentials by the user, may be used as a two-factor authentication,such that entry of a correct PIN or password may serve as a firstfactor, and the way or pattern or behavioral traits or other-specifictraits of the way in which the user enters the PIN or password may serveas a second factor.

In a first example, the user may be required to enter a four-digit PIN.An on-screen keypad may be shown to the user, showing ten digits (from 0to 9), and showing four empty “slots” into which the user is requestedto “drag and drop” digits, one digit at a time. The user may drag thefour digits of his PIN, to the four respective slots, in the rightorder. If the four digits dragged match (in their right order) theuser's stored PIN, then a first factor of authentication is met. If theway in which the user drags-and-drops the digits onto the slots, matchespreviously-recorded information that indicates how the user typicallyperforms such GUI operation, then a second factor of authentication maybe met.

In a second example, alphabetical characters, or alpha-numericcharacters, or other characters, may be presented to the user as anon-screen keyboard, and the user may drag characters from it towardsslot(s) or a field into which the password or PIN is accumulated; andthe system may monitor and utilize both the correct entry of the PIN orpassword, as well as the manner in which the user utilizes the GUI toachieve such correct entry.

In a third example, as part of a user authentication process or a userlogin process, digits (or letters, or characters) are shown on rollerswhich may be similar to a slot-machine; and the user may need to shiftor turn or roll such rollers in order to reach a particular digit (orletter, or character) on each roller. The correctness of the PIN, aswell as the way in which the user utilizes the GUI to reach the correctPIN, may serve as two-factor authentication.

In a fourth example, the log-in process may include PIN entry as well asperforming a simple game-like operation, such as, correctly assembling apuzzle having few pieces (e.g., less than ten pieces). The way in whichthe user utilizes the GUI to assemble the puzzle, may be used as afactor in user authentication, in addition to the correct entry of thePIN or password value.

In some embodiments, the system may utilize a “training period” of, forexample, ten user-authentication sessions, in which the system maymonitor and track how the user utilizes the GUI to enter his PIN orpassword. For example, the system may observe and recognize that theuser typically drags a first digit of his PIN in a straight shortdiagonal line, then he drags a second digit of his PIN in a long curvedline, or the like, then he pauses a little longer before dragging thethird digit, and so forth. The system may generate a user-specificprofile that corresponds to such user-specific insights. Subsequently,when the user again logs-in, the system monitors the correctness of hisPIN as well as whether the manner in which the user enters his PINmatches his previously-generated profile of GUI utilization, as atwo-factor authentication scheme. In some embodiments, if the currentmanner of GUI utilization does not match the previously-determineduser-specific profile of GUI utilization, then the system may declarethat the user failed to authenticate, or that a possible fraud exists.

In some embodiments, the present invention may be used to facilitate aprocess of PIN-reset or password-reset. For example, a PIN-reset processmay require the user to enter his current PIN, both by entering thecorrect PIN value as well as (without the user necessarily knowing) inthe particular GUI-utilization manner that matches his user-specificprofile. If both factors are met, then PIN-reset may be enabled, withoutthe need to utilize a complex process in which the user is alsocontacted by phone or by email.

In some embodiments, a tolerance-for-mistakes modification module 259may be utilized to increase (or decrease, or modify) the system'stolerance for mistakes (or failed attempts) made by the user in anauthentication process. For example, a demonstrative system may allowthree consecutive failed attempts in logging-in, and may then “lock” theaccount and may require that the user (e.g., a bank customer) to call acustomer service number for further handling. However, if the presentinvention is utilized, some embodiments may recognize that althoughthree failed log-in attempts were performed, they were all performed ina GUI-utilization manner that closely matches the previously-storeduser-specific profile of GUI utilization; and therefore, the system maybecome more “forgiving” and may allow such user one more (or a few more)log-in attempts before “locking” the account or putting the process onhold.

In some embodiments, the system may periodically update theuser-specific GUI-utilization profile, based on the ongoing utilizationby the user. For example, the user may start utilizing the system onJanuary 1st, and the system may utilize ten log-in sessions, performedin January, for generating an initial user-specific profile of GUIutilization. The system may proceed to utilize the generated profile,during 25 subsequent log-in profiles of that user, in the months ofFebruary through June. The system may continue to update theuser-specific profile, based on log-in sessions as they take place.Optionally, the system may discard historic data of GUI-utilization(e.g., in a First-In-First-Out (FIFO) order), since, for example, a usermay change the way he utilizes the GUI over time, due to learning thesystem better, becoming more familiar with the system, getting older inage, or the like. In some embodiments, the system may continuouslyupdate the user-specific profile of GUI utilization.

Some embodiments may a login process which may comprise one or morechallenges to the user, that the user may not be aware of, or that theuser may perform without being aware that the system is checkingadditional parameters about the user (other than the user's credentials,e.g., username and password).

In a first demonstrative example, a Visual Login module 262 may generateand display an on-screen user interface which requires the user toperform on-screen operations in order to log-in to a service, such thatthe on-screen operations to be performed by the user may require theuser to perform input-unit interactions (e.g., mouse-clicks, mousemovement, keystrokes, or the like) that may be monitored by the system,and such that user-specific traits may be extracted from such input-userinteractions, with or without introducing (or injecting) an interferenceto the on-screen log-in process or to the user experience of the visuallogin process.

In a more particular example, the Visual Login module 262 may present anon-screen interface showing an on-screen keypad (or keyboard) and a“target” zone (or field, or area); and the user may be requested todrag-and-drop digits (or letters, or character), one by one, in theircorrect order, from the on-screen keypad (or keyboard) to the targetzone, thereby filling-in the user's credentials (e.g., username,password, PIN, or the like). The system may monitor the way that theuser drags-and-drops the on-screen items (e.g., digits, letters,characters) from the on-screen keypad (or keyboard) to the on-screentarget zone; and may extract user-specific traits from suchinteractions. For example, a first user may drag a particular digit(e.g., the first digit in his PIN; or the digit “4”) in a straight orgenerally-straight line, whereas a second user may drag that particulardigit in a curved line, or in a line having certain attributes (e.g.,counter-clockwise direction), or the like. The system may store, in auser's profile or record, data indicating the user-specific trait thatwas extracted from those interactions; as well as other suitableparameters which may be extracted or computed based on the sampling ofthe input-device interactions during such Visible Login process (e.g.,average time or speed associated with the login process; indicativepauses between entry of particular characters, or before or afterentering a particular character; or the like). In a subsequent loginprocess, the extracted user-specific traits may be utilized fordifferentiating or distinguishing between a first user and a seconduser; or between a genuine (legitimate) user and a fraudster (orunauthorized user).

In another example, the Visual Login module 262 may operate inconjunction with one or more interference(s), which may be introduced orinjected to the visual login process. For example, the Visual Loginmodule 262 may introduce a randomly-selected interference (e.g.,selected pseudo-randomly from a pool of several or numerous pre-definedtypes of interferences), or may introduce a pre-defined interference orset of interferences. For example, when the user drags the secondcharacter from the on-screen keypad to the on-screen target zone, theon-screen dragged character may suddenly appear to be “stuck” for threeseconds, or may appear to “jump” 200 pixels to the left side of itscurrent location; and the system may monitor the user's reaction to suchinterference(s), e.g., how long it takes the user to notice theinterference and/or to take corrective actions, which type of correctiveaction the user takes (e.g., shaking the mouse unit sideways, orspinning the mouse-device clockwise, or clicking the mouse severaltimes), and/or other attributes or parameters of the specific correctiveaction (e.g., if the user shakes his mouse unit, for how many times isit shaken, or the direction of shaking, or the direction of rotation, orthe like). In a subsequent login process, the extracted user-specifictraits may be utilized for differentiating or distinguishing between afirst user and a second user; or between a genuine (legitimate) user anda fraudster (or unauthorized user); for example, by injecting the sametype of interference to the accessing user, and by monitoring whether ornot the current user's reaction to the interference matches thepreviously-extracted user-specific traits.

Some embodiments may utilize other types of on-screen visual loginprocess, which may not necessarily involve drag-and-drop operations. Forexample, an on-screen “vault” may be displayed to the user, with wheelsor bolts or cylinders that the user may be required to spin or to rotate(e.g., with one or two or three fingers on a touch-screen), in order toenter a combination which corresponds to the user's PIN. Other types ofchallenges may be used, optionally having game elements or game-likeelements, and optionally hiding from the user the fact that the systemmay implicitly track user-specific patterns of interactions as part ofauthenticating the user.

Some embodiments may thus allow or enable the system to perform animplicit Two-Factor Authentication (TFA) process (or two-stepauthentication process), without the explicit knowledge of the user. Forexample, the implicit TFA process may combine a first factor (“somethingyou know”) with a second factor (“something you have”), such that, forexample, the first factor may be the user's knowledge of his PIN orpassword (e.g., the entered password or PIN matches thepreviously-defined PIN or password of that user); and the second factormay be the user's particular way of handling of the input-unit, eitheras general handling, or as a particular handling in response to aninterference injected to the login process. The system may thusimplement TFA without requiring the user, for example, to utilize atoken device for generating a one-time password, or without requiringthe user to receive a one-time password via text message or emailmessage or voice message; and without even the actual knowledge of someusers that the authentication process is actually an implicit TFAprocess.

In some embodiments, the visual login (or visible login) process may beimplemented by utilizing one or more of the following:

(1) Drag-and-drop of digits or letters or characters, from an on-screenkeypad or keyboard, to an on-screen target zone, while monitoringuser-specific interaction patterns, without injecting a user-interfaceinterference, and/or in response to an injected user-interfaceinterference.

(2) Rotating or spinning of on-screen “vault” elements or cylinders inorder to enter a PIN, while monitoring user-specific interactionpatterns, without injecting a user-interface interference, and/or inresponse to an injected user-interface interference. The system maymonitor one or more attributes of the input-user interactions, or of theuser interactions, in order to extract or construct a user-specificpattern or model or profile; for example, reflecting or correspondingto: (a) whether the user rotates a cylinder clockwise orcounter-clockwise; (b) whether the user utilizes one finger, or twofingers, or three fingers, in order to perform a rotation operation; (c)whether the user typically uses a top-area (or a bottom-area, or aright-area, or a left-area) of the cylinder in order to perform therotation, or two particular (e.g., opposite) areas of the cylinder inorder to perform the rotation; (d) the arrangement, distance and/orspacing between two or more fingers that the user utilizes for rotatingthe cylinder (e.g., measured via on-screen pixels distance betweenpoints of touching the touch-screen); (e) relative movement of eachfinger that is used for rotation, since not all fingers may moveuniformly or at the same speed or to the same direction; (f) time-lengthor duration that it takes the user to perform a rotation; (g) whetherthe user typically performs one long rotation movement, or performsmultiple shorter rotation movement, in order to achieve a rotationresult of a particular type (e.g., a rotation result that requiresrotation by at least 180 degrees); or the like. Optionally, one or moreuser-interface interferences or abnormalities may be injected orintroduced; for example, causing an on-screen cylinder to become “stuck”or non-responsive for a pre-defined period of time (e.g., five seconds),causing an on-screen cylinder to rotate faster or slower relative to therotation of the fingers of the user or to continue rotating after theuser stopped his rotating gesture); and a user-specific profile orpattern may be extracted, based on the user's reactions to suchinterference. In a subsequent usage session or log-in session, animplicit TFA process may thus be able to verify that both: (a) the userknows and enters the correct credentials, and (b) the user enters thecredentials in a manual manner that corresponds to (or matches) theuser-specific profile that indicates how this user has previouslyreacted to such interference.

(3) Entering user credentials (e.g., username, password, PIN, or thelike), optionally by utilizing the on-screen interface mentioned in (1)above, while de-activating the Enter (or Return) key on the keyboard,thereby requiring the user to click or tap on an on-screen “submit”button (since the Enter or Return key is non-responsive), and whileintroducing an interference or abnormality to the on-screen “submit”button (e.g., the on-screen “submit” button is non-responsive for apredefined time period, or the on-screen “submit” button isnon-responsive for a pre-defined number of clicks, or the on-screen“submit” button is being moved sideways upon approach of the user'spointer; and while monitoring user-specific interaction patterns;thereby allowing the system to perform implicit TFA, by examiningwhether the user knows the corrected credentials (e.g., password orPIN), and also, whether the user's input-unit interactions (in responseto the injected user-interface interference) match the previoususer-specific pattern or profile or reaction to such interference.

(4) Presenting an on-screen collection of items (e.g., ten images ofvarious objects or animals); and requesting the user to drag-and-drop,on the screen, one particular item from the collection, based on verbalor textual description that the user has to comprehend in order to matchwith the correct image; such as, “please drag the image of a Dog to thetarget zone”, or “please drag the image that shows a Fruit to the targetzone”. While the user performs the drag-and-drop operation, the systemmay introduce a user-interface interference (e.g., the dragged itemsuddenly deviates sideways, or suddenly freezes or appears to be“stuck”), and the system may monitor the user's reaction orcorrective-action to such interference. Subsequently, such login processmay be utilized to verify that the person is human (since he needs tocomprehend and process the textual request with the instruction in orderto decide which on-screen item to drag from the collection) and that thehuman user is the genuine user (e.g., who previously logged-in to theservice) based on matching of the user's reaction to the interferencewith a user-specific profile or pattern of reactions to suchinterference in previous usage sessions.

(5) Adding or introducing, intentionally, a delay or time-gap (which maybe constant, or pseudo-random within a particular range of values),between: (a) the pressing or tapping or clicking of a character that theuser clicks or taps or presses, as part of entering user credentials;and (b) the appearance of the character on the screen (or, theappearance of an additional “*” or “x” character which indicates that apassword is being entered); while measuring the user-specific reactionor pattern-of-reactions to such injected delay or time-gap; andutilizing the user-specific pattern or profile of reactions as a means(or as additional means) in subsequent log-in sessions, or to detectfraudulent users, or to differentiate between users.

(6) Presenting an on-screen puzzle (e.g., a simple jigsaw puzzle) thatthe user has to solve or complete, by using drag-and-drop operations;monitoring and capturing user-specific cognitive choices (e.g., whetherthe user typically drags a right-side of the puzzle into the left-side,or whether the user typically drags the left-side of the puzzle into theright side; whether the user solves the puzzle in particular direction,or clockwise, or counter-clockwise, or in a sequence such that eachselected piece is the closest to the previously-dragged piece); andoptionally by introducing a user-interface interference to the processof solving the puzzle (e.g., a puzzle piece appears to be non-responsiveor stuck for a pre-defined time period; a puzzle piece deviates orshifts away from the dragging-route that the user commanded with hisgestures), and monitoring the user's reactions to such interference inorder to extract a user-specific pattern or profile, which may then beused for user authentication or user differentiation purposes.

Optionally, system 200 may comprise a stochastic cryptography module260, able to utilize stochastic cryptology and/or stochasticcryptography for various purposes such as remote access. For example,the stochastic cryptography module 260 may utilize cognitive aberrationsor interruptions or interferences in order to monitor and utilize theresponse or reaction of the user for cryptographic tasks orcryptographic-related tasks (e.g., encryption, decryption, hashing,digital signing, authorizing, verification, or the like). The human usermay be subjected to an aberration or interference (which may be selectedby the system pseudo-randomly from a pool of pre-defined types ofinterferences), and thus may produce a reaction which may beuser-specific and have some non-predictable properties (e.g., since eachuser reacts differently to each interference, and since the particularinterference is selected pseudo-randomly from a pool of possibleinterference types)

In a demonstrative embodiment, system 200 may monitor the manner inwhich a user reacts to a user interface interference, that is selectedby the system 200 from a pool of pre-defined types of interferences; forexample, an interference in which the on-screen pointer appears to be“stuck” or non-responsive; an interference in which the on-screenpointer disappears for a pre-defined time period; an interference inwhich the on-screen pointer moves erratically, or moves in a manner thatis not identical to the route of the movement of the input unit. Theuser reaction, or the corrective action by the user in response to suchinterference, may be monitored and analyzed by the system 200, and auser-specific reaction model may be extracted, on a per-userper-interference-type basis. This user-specific interference-specificreaction model may be used as a parameter known by the system in orderto implement an algorithm (e.g., encryption, decryption) that utilizesstochastic cryptography or probabilistic cryptography.

For example, if a user requests to encrypt a document or file or digitalasset or digital content item, then the encryption key (or theencryption algorithm) may utilize a user-specific parameter that hasbeen previously extracted by the system by monitoring the user'sreaction to a specific interference-type (e.g., as one of the multipliernumbers in establishing a unique product-of-multiplication number whichmay be used as encryption key). Similarly, in order to decrypt such anencrypted document or file or digital asset, then the system mayintroduce to the user an interference of the type of interferences thathad been used to generate a key in the encryption process; may monitorthe user's reaction to the interference; and may extract a user-specificparameter from the monitored user-specific reaction, which may then beused as part of the decryption process (and may be required forsuccessful decryption). In some implementations, theencryption/decryption (or other cryptographic) algorithm may bestochastic or probabilistic, as it may sometimes fail to perform thecryptographic operation since the user's reaction to an interference ina particular instance may not be exactly identical to the user'sprevious reactions (which had been used in the encryption process);however, such errors may be estimated in advance and/or may beminimized, by taking into account probabilistic consideration.

For example, if it is estimated or observed that one-out-of-four timesthe user's reaction may not match a previously-calculated model ofreaction to interference, then, in one-out-of-four attempts to accessthe encrypted data, the user may fail even though the user was thegenuine user; however, the system may request the user to “try again”,by introducing to the interface a same-type interference (e.g., the sameinterference-type, but the interference being of a differentorder-of-magnitude or scale), and upon such “further attempt” by theuser, the system may extract a user-reaction which corresponds to thepreviously-calculated model, which had been used as a parameter in theencryption process.

In some embodiments, the stochastic encryption process may beimplemented as follows. Initially, an enrollment phase or initiationstage may be performed, in order to monitor and measure the reaction(s)of a particular user to a variety of interferences that are presented tothe user, one interference at a time, from a pre-defined pool ofpossible interferences (e.g., the pool having 5 or 15 or 60 or 100 or250 or 500 or 800 such interferences, or interference-types, orapproximately 200 to 900 interferences, or approximately 400 to 600interferences). Then, the system may generate a user-specific model orprofile, which indicates how the particular user reacts tointerference(s) in general (“user-specific general reaction model”),and/or how the particular user reacts to a particular interference (toseveral particular interferences) in particular (“user-specificparticular reaction model”).

Subsequently, after the user-specific general reaction model isestablished, the system may utilize the user-specific general reactionmodel (or, one or more values of parameters of the user-specific generalreaction model) as a parameter for encryption (e.g., for generating anencryption key, or for generating a private encryption key, or otherwiseas part of an encryption algorithm. From that time-point and onward, theuser-specific general reaction model (and/or any of its parameters) arenot transferred, are not transmitted, and are not communicated among anytwo or more devices or units or entities. This may be in contrast with,for example, a process that utilizes a user's fingerprint as a parameterfor encryption; which subsequently requires the user to provide hiscurrent fingerprint every time that the user desires to access ordecrypt such encrypted content.

Subsequently, in order to decrypt the encrypted content, the system maypresent to the user an “invisible challenge”, namely, an implicitchallenge that the user may respond to without even knowing that achallenge-response process is taking place; and in each decryptionrequest (or decryption attempt) that the use initiates, the system maypresent to the user a different type of invisible challenge from thepool of interferences that had been used by the system in order to buildthe user-specific general reaction model of that user; optionally byusing or re-using a particular interference (or type of interference)while modifying or increasing or decreasing the scale or theorder-of-magnitude of the interference or of one or more parameters ofthat interference or interference-type. Accordingly, the decryptionprocess requires the user to react to a single particular interferenceout of the set of interferences that were used for generating theuser-specific general reaction model; and the decryption processmonitors and measures the user's reaction to the single, presented,interference.

Therefore, an attacker or a “listening hacker” that monitors thecommunication channel during an encryption request, or during multiple(series of) encryption requests, can see one single interference at atime, and one single user-specific reaction at a time to the presentedsingle interference. Accordingly, such listening attacker may not beable to reverse-engineer or to estimate the user-specific generalreaction model, which was computed based on numerous differentinterferences presented in series, and which was the basis forgenerating the encryption key or for generating encryption-relatedparameters. Optionally, in order to further burden a potential attacker,the original pool of possible interference may comprise hundreds or eventhousands of various different interferences and/or interference-types,having various scales or orders-of-magnitude.

As a further clarification, the encryption process may be regarded as aprocess that generates and utilize a “generator function” able togenerate random or pseudo-random numbers. The generator function existson both sides; namely, e.g., on the system's stochastic encryptionmodule which monitored and generated the user-specific general reactionmodel; and at the genuine user's side because the genuine user is ableto react “correctly” to each particular interference, similarly to hispreviously-monitored reactions to such interference. The generatorfunction is able to generate a similar (or identical) sequence or seriesof random (or pseudo-random) numbers, which are then used as a parameterfor encryption; whereas, each decryption operation requires only oneparticular number from the series of random numbers that were used forthe encryption. Accordingly, a listening attacker may be able toobserve, at most, random values transmitted from the genuine user's sideto the server, and may not be able to reverse-engineer or to estimate orto guess the “generator function” itself, and may not be able to predictor to guess or to estimate the next particular number that might be usedin a subsequent decryption request. The generator function (which isused for encryption) may correspond to the user-specific generalreaction model; whereas, the particular number for a particulardecryption operation may correspond to the particular reaction of thespecific user to a particular interference (out of a large set ofinterferences that had been used in order to generate the user-specificgeneral reaction model for encryption purposes).

The present invention may thus provide various advantages and/orbenefits, for cryptographic purposes. For example, a deterministicgenerator function might be subject to reverse-engineering orestimation, if an attacker listens to (or intercepts) asufficiently-large number of random numbers generated by thedeterministic generator function; whereas, the stochastic generatorfunction of the present invention, which is based on the user-specificgeneral reaction model, may not be reverse-engineered or estimated evenif the attacker listens to a large number of values transmitted in aseries of decryption requests; and the stochastic generator function maynot be easily reverse-engineered or estimated since it is not based on adeterministic mathematical function.

Additionally or alternatively, each decryption attempt, in accordancewith the present invention, requires an actual hands-on interaction ofthe user (or the attacker) with an input unit; thereby heavily burdeningany attempt to implement a brute-force attack, or rendering such attacknon-cost-effective, or requiring manual interaction for such brute-forceattack, or requiring a significant amount of time for such brute-forceattack; for example, since an attacker may not be able to merelyautomatically transmit a sequence of numbers (or values) withoutperforming the hands-on manual human interaction that requires time forperformance by the genuine user.

It is clarified that in some implementations, the stochasticencryption/decryption process may trigger “false positive” errors; suchthat, for example, a genuine user may not be able to decrypt hisencrypted file (or content, or digital asset) even though the genuineuser has reacted “correctly” to the specific invisible challenge (orinterference) presented to him; and thus, two or more “correct” attempts(of reaction to interference) may sometimes be required, in order toallow a genuine user to decrypt his encrypted content. As describedabove, a deterministic or mathematic generator function always producesthe same random numbers on both sides; whereas, the stochasticcryptography of the present invention may sometimes generatenon-identical random numbers on both sides, since one side (the server'sside) utilizes the previously-computed user-specific general reactionmodel, whereas the other side (the genuine user's side) utilizes theactual current reaction of the specific user, which may sometime deviatefrom the user's previous reactions that were used for generating theuser-specific general reaction model.

It is clarified that terms such as, for example, “interference”, “userinterface interference”, “input unit interference”, “UI interference”,“GUI interference”, “UI element interference”, “on-screen interference”,“input process interference”, “visual interference”, “visibleinterference”, “aberration”, “perturbation”, “abnormality”, “anomaly”,“irregularity”, “perceived malfunction”, “temporary malfunction”,“invisible challenge”, “hidden challenge”, or other similar terms, maybe used interchangeably; and may refer to one or more processes oroperations in which an irregularity is introduced or generated orinjected into a user-interface or is burdening or altering or modifyinguser interactions, or is generated in order to induce or elicit reactionor reactive action or corrective action in response to suchinterference(s); or a combination of two or more such interferences,introduced in series or in parallel or simultaneously, over one or moreUI element(s) or GUI elements.

In some embodiments, a mood estimator 261 may continuously identify orestimate the mood or feelings of the user (e.g., a customer thatutilizes an electronic device), when the user utilizes a website or anapplication. This may be used in order to adjust or modify or tailormessages (e.g., advertisements, proposals, promotions, businessofferings) to the user. The system may inject cognitive aberrations orinterferences to the interaction between the user and the application orwebsite; and may monitor and measure the reaction of the user. The moodestimator 261 may compare between the current specific reaction of theuser, and a historic profile of the user; and may identify parameters,for example, level of concentration or focusing, response speed, mannerof reaction, or the like; thereby allowing a marketing/sales module orsub-system (which may be associated with the website or application) tofurther analyze the purchase-related and/or viewing-related (orbrowsing-related) behavior of the user by utilizing such parameters, inorder to tailor or modify marketing proposals or other contentdisplayed, to the particular cognitive state of the user as estimated atthat time based on the user's reactions to injected interferences.

The terms “mobile device” or “mobile electronic device” as used hereinmay include, for example, a smartphone, a cellular phone, a mobilephone, a tablet, a handheld device, a portable electronic device, aportable gaming device, a portable audio/video player, or the like.

The term “pointing device” as used herein may include, for example, amouse, a trackball, a pointing stick, a stylus, a joystick, amotion-sensing input device, a touch screen, a touch-pad, or the like.

The term “device” or “electronic device” as used herein may include, forexample, a mobile device, a non-mobile device, a non-portable device, adesktop computer, a workstation, a computing terminal, a laptopcomputer, a notebook computer, a netbook computer, a computing deviceassociated with a mouse or a similar pointing accessory, or the like.

The term “genuine user” as used herein may include, for example, anowner of a device; a legal or lawful user of a device; an authorizeduser of a device; a person who has legal authorization and/or legalright to utilize a device, for general purpose(s) and/or for one or moreparticular purpose(s); or the person who had originally defined usercredentials (e.g., username and password) for performing an activitythrough the device.

The term “fraudulent user” as used herein may include, for example, anyperson who is not the “genuine user” of the device; an attacker; anintruder; a man-in-the-middle attacker; a man-in-the-browser attacker;an unauthorized user; an impersonator; a hacker; a cracker; a personattempting to hack or crack or compromise a security measure utilized bythe device or by a system or a service or a website, or utilized by anactivity or service accessible through the device; a fraudster; a humanfraudster; a “bot” or a malware or an automated computerized process(e.g., implemented by using software modules and/or hardware components)which attempts to imitate human behavior or which attempts to act as ifsuch “bot” or malware or process was the genuine user; or the like.

The present invention may be used in conjunction with various suitabledevices and systems, for example, various devices that have atouch-screen; an ATM; a kiosk machine or vending machine that has atouch-screen; a touch-keyboard; a system that utilizes Augmented Reality(AR) components or AR glasses (e.g., Google Glass); a device or systemthat may detect hovering gestures that do not necessarily touch on thescreen or touch-screen; a hovering screen; a system or device thatutilize brainwave analysis or brainwave control in which the user'sbrainwaves are captured or read and the user's brain may directlycontrol an application on the mobile device; and/or other suitabledevices or systems.

Some embodiments may identify multiple (different) users that utilizethe same device, or the same account, before or after a typical userprofile is built, or even during a training period in which the systemlearns the behavioral patterns. This may be used for detection of“friendly fraud” incidents, or identification of users foraccountability purposes, or identification of the user that utilized aparticular function in an Administrator account (e.g., optionally usedin conjunction with a requirement that certain users, or users withcertain privileges, may not share their password or credentials with anyother person); or identification of a licensee in order to detect orprevent software piracy or unauthorized usage by non-licensee user(s),for software or products that are sold or licensed on a per-user basisor a per-seat basis.

In some embodiments, the present invention may be utilized to decrease(or increase, or modify) friction from an authentication process. Forexample, after a login form was filled and submitted by the user, ademonstrative system may skip or not skip an additional authenticationstep (e.g., a security question) if the system recognizes the user asthe genuine user.

Some embodiments may identify or detect a remote access attacker, or anattacker or a user that utilizes a remote access channel to access (orto attack, or to compromise) a computerized service.

In some embodiments, a method comprises: determining whether a user, whoutilizes a computing device to interact with a computerized service, (i)is co-located physically near said computing device, or (ii) is locatedremotely from said computing device and controlling remotely saidcomputer device via a remote access channel; wherein the determiningcomprises: (a) injecting, to a user interface of said computerizedservice, an interference which affects differently local users andremote users; (b) monitoring interactions of the user with an inputunit, in response to said interference; (c) based on said monitoring,determining whether said user (i) is co-located physically at saidcomputing device, or (ii) is located remotely from said computing deviceand controlling remotely said computing device via said remote accesschannel.

In some embodiments, the determining of step (c) is based on a latencybetween (A) the injecting of said interference, and (B) the input unitinteractions of said user in response to said interference.

In some embodiments, the determining of step (c) is based on a type ofreaction of said user to the injecting of said interference.

In some embodiments, the method comprises: hiding a mouse-pointer on ascreen of said computerized service; monitoring input unit reactions ofsaid user in response to the hiding of the mouse-pointer; based on theinput unit reactions of said user in response to the hiding of themouse-pointer, determining whether said user is (i) co-locatedphysically at said computing device, or (ii) is located remotely fromsaid computing device and controlling remotely said computing device viasaid remote access channel.

In some embodiments, the method comprises: replacing an originalmouse-pointer on a screen of said computerized service, with a fakemouse-pointer deviated from a location of said original mouse-pointer;monitoring input unit interactions of said user when the fakemouse-pointer is displayed on said computing device that is accessingsaid computerized service; based on the input unit interactions with thefake mouse-pointer, determining whether said user is (i) co-locatedphysically at said computing device, or (ii) is located remotely fromsaid computing device and controlling remotely said computing device viasaid remote access channel.

In some embodiments, the method comprises: sampling multipleinteractions of said user with said input unit; based on a frequency ofsaid sampling, determining whether said user is (i) co-locatedphysically at said computing device, or (ii) is located remotely fromsaid computing device and controlling remotely said computing device viasaid remote access channel.

In some embodiments, the method comprises: sampling multipleinteractions of said user with said input unit; based on a level ofnoise in said sampling, determining whether said user is (i) co-locatedphysically at said computing device, or (ii) is located remotely fromsaid computing device and controlling remotely said computing device viasaid remote access channel.

In some embodiments, the method comprises: sampling multipleinteractions of said user with a computer mouse; if said samplingindicates generally-smooth movement of the computer mouse, then,determining that said user is co-located physically near said computingdevice.

In some embodiments, the method comprises: sampling multipleinteractions of said user with a computer mouse; if said samplingindicates generally-rough movement of the computer mouse, then,determining that said user is located remotely from said computingdevice and controlling remotely said computing device via said remoteaccess channel.

In some embodiments, the method comprises: sampling multipleinteractions of said user with a computer mouse; if said samplingindicates generally-linear movement of the computer mouse, then,determining that said user is located remotely from said computingdevice and controlling remotely said computing device via said remoteaccess channel.

In some embodiments, the method comprises: sampling multipleinteractions of said user with a computer mouse; if said samplingindicates sharp-turn movements of the computer mouse, then, determiningthat said user is located remotely from said computing device andcontrolling remotely said computing device via said remote accesschannel.

In some embodiments, the method comprises: sampling multipleinteractions of said user with said input unit; if a frequency of saidmultiple interactions is below a pre-defined threshold, then,determining that said user is located remotely from said computingdevice and controlling remotely said computing device via said remoteaccess channel; if the frequency of said multiple interactions is abovethe pre-defined threshold, then, determining that said user isco-located physically near said computing device.

In some embodiments, the method comprises: overloading one or moreresources of the computing device which is used for accessing saidcomputerized service; measuring an effect of said overloading onfrequency of sampling user interactions via an input unit; based on themeasured effect of said overloading, determining whether said user is(i) co-located physically at said computing device, or (ii) is locatedremotely from said computing device and controlling remotely saidcomputing device via said remote access channel.

In some embodiments, the method comprises: overloading a data transfercommunication channel of the computing device that is used for accessingsaid computerized service; measuring an effect of said overloading onfrequency of sampling user interactions via an input unit; based on themeasured effect of said overloading, determining whether said user is(i) co-located physically at said computing device, or (ii) is locatedremotely from said computing device and controlling remotely saidcomputing device via said remote access channel.

In some embodiments, the method comprises: overloading a screen displayof the computing device that is used for accessing said computerizedservice; measuring an effect of said overloading on frequency ofsampling user interactions via an input unit; based on the measuredeffect of said overloading, determining whether said user is (i)co-located physically at said computing device, or (ii) is locatedremotely from said computing device and controlling remotely saidcomputing device via said remote access channel.

In some embodiments, the method comprises: displaying an instantaneouspriming message on a screen of the computing device that is utilized foraccessing said computerized service; measuring an effect of theinstantaneous priming message on sampled user interactions via an inputunit; based on the measured effect of said instantaneous primingmessage, determining whether said user is (i) co-located physically atsaid computing device, or (ii) is located remotely from said computingdevice and controlling remotely said computing device via said remoteaccess channel.

In some embodiments, the method comprises: injecting, into a log-inscreen of the computerized service, a user interface interference thatcauses non-remote users to perform corrective mouse gestures;immediately after a log-in into the computerized service, displaying asubsequent screen of the computerized service without said userinterface interference; monitoring mouse gestures of the user in thesubsequent screen; if the monitored mouse gestures in the subsequentscreen comprise corrective mouse gestures, then, determining that a userof the subsequent screen is a local user located physically at thecomputing device; if the monitored mouse gestures in said subsequentscreen lacks corrective mouse gestures, then, determining that a user ofthe subsequent screen is located remotely from said computing device andcontrolling remotely said computing device via said remote accesschannel.

In some embodiments, the method comprises: sampling user interactionswith an input unit of said computing device; based on said sampling,determining that said user is utilizing a first set of hardwarecomponents which is capable of sampling the input unit at a firstfrequency; subsequently, (A) sampling additional, subsequent userinteractions; (B) determining that a second, lower, frequencycharacterizes said subsequent sampling; (C) determining that a second,different, set of hardware components is being used; (D) determiningthat a non-authorized person is accessing said computerized service.

In some embodiments, the method comprises: sampling user interactionswith an input unit of a mobile computing device; analyzing temporalrelationship between touch and accelerometer events of sampled userinteractions with said input unit of the mobile computing device; basedon analysis of temporal relationship between touch and accelerometerevents, of sampled user interactions with said input unit of the mobilecomputing device, determining whether the said mobile computing deviceis controlled remotely via said remote access channel.

In some embodiments, the method comprises: sampling user interactionswith an input unit of a mobile computing device; analyzing temporalrelationship between touch movement events and accelerometer events, ofsampled user interactions with said input unit of the mobile computingdevice; based on analysis of temporal relationship between touchmovement event and accelerometer events, of sampled user interactionswith said input unit of the mobile computing device, determining whetherthe said mobile computing device is controlled remotely via said remoteaccess channel.

In some embodiments, the method comprises: (A) sampling touch-basedgestures of a touch-screen of a mobile computing device; (B) samplingaccelerometer data of said mobile computing device, during a time periodwhich at least partially overlaps said sampling of touch-based gesturesof the touch-screen of the mobile computing device; (C) based on amismatch between (i) sampled touch-based gestures, and (ii) sampledaccelerometer data, determining that the mobile computing device wascontrolled remotely via said remote access channel.

In some embodiments, the method comprises: (A) sampling touch-basedgestures of a touch-screen of a mobile computing device; (B) samplingaccelerometer data of said mobile computing device, during a time periodwhich at least partially overlaps said sampling of touch-based gesturesof the touch-screen of the mobile computing device; (C) determining thatsampled touch-based gestures indicate that a user operated the mobilecomputing device at a particular time-slot; (D) determining that thesampled accelerometer data indicate that the mobile computing device wasnot moved during said particular time-slot; (E) based on the determiningof step (C) and the determining of step (D), determining that the mobilecomputing device was controlled remotely via said remote access channelduring said particular time-slot.

In some embodiments, a comprises: a user identity determination moduleto determine whether a user, who utilizes a computing device to interactwith a computerized service, is either (i) co-located physically nearsaid computing device, or (ii) located remotely from said computingdevice and is controlling remotely said computer device via a remoteaccess channel; wherein the user identity determination module is: (a)to inject, to a user interface of said computerized service, aninterference which affects differently local users and remote users; (b)to monitor interactions of the user with an input unit, in response tosaid interference; (c) based on the monitored interactions, to determinewhether said user (i) is co-located physically at said computing device,or (ii) is located remotely from said computing device and controllingremotely said computing device via said remote access channel.

In some embodiments, the user identity determination module is todetermine in step (c), based on a latency between (A) injection of saidinterference, and (B) the input unit interactions of said user inresponse to said interference.

In some embodiments, the user identity determination module is todetermine in step (c), based on a type of reaction of said user to theinjecting of said interference.

Some embodiments may detect a malicious automatic script, and/or maydetect malicious code injection (e.g., malicious HTML code injection).

In some embodiments, a method comprises: determining whether a user, whoutilizes a computing device to interact with a computerized service, (i)is a human user, or (ii) is an automatic script executed by a processor;wherein the determining comprises: (a) monitoring user-side input-unitinteractions performed through one or more input units; (b) matchingbetween (A) the user-side input-unit interactions and (B) data sentelectronically from said computerized service; (c) if the comparingresult is that (A) the user-side input-unit interactions do not exactlymatch (B) the data sent electronically from said computerized service,then determining that the computing device is operated by automaticscript executed by said processor.

In some embodiments, the method comprises: based on the monitoring ofthe user-side input-unit interactions, detecting absence of anyuser-side input-unit interactions within a pre-defined time periodduring which the computing device transmitted data to the computerizedservice; based on detecting absence of any user-side input-unitinteractions within said pre-defined time period, determining whetherthe computing device is operated by automatic script executed by saidprocessor.

In some embodiments, the method comprises: based on the monitoring ofthe user-side input-unit interactions, detecting a number of keystrokesentered via a keyboard within a pre-defined time period during which thecomputing device transmitted data to the computerized service;determining a total number of keystrokes that a human is expected tomanually enter in order to cause the computing device to transmit saiddata to the computerized service; based on matching between (A) thenumber of keystrokes entered via the keyboard, and (B) the total numberof keystrokes that the human is expected to manually enter, determiningwhether the computing device is operated by automatic script executed bysaid processor.

In some embodiments, the method comprises: based on the monitoring ofthe user-side input-unit interactions, determining that keystrokesentered via a keyboard, within a pre-defined time period during whichthe computing device transmitted data to the computerized service,correspond to: (a) a first batch of keystrokes having a firstkeystrokes-length; and (b) a second batch of keystrokes having a secondkeystrokes-length; determining that the data transmitted from thecomputing device to the computerized service corresponds to: (A) a firststring having a first string-length; and (B) a second string having asecond string-length; based on matching between the firstkeystrokes-length and the first string-length, determining whether thecomputing device is operated by automatic script executed by saidprocessor.

In some embodiments, the method comprises: based on the monitoring ofthe user-side input-unit interactions, determining that keystrokesentered via a keyboard, within a pre-defined time period during whichthe computing device transmitted data to the computerized service,correspond to: (a) a first batch of keystrokes having a firstkeystrokes-length; and (b) a second batch of keystrokes having a secondkeystrokes-length; determining that the data transmitted from thecomputing device to the computerized service corresponds to: (A) a firststring having a first string-length; and (B) a second string having asecond string-length; wherein a total of the first and secondkeystrokes-length, is equal to a total of the first and second stringlengths; based on matching between the first keystrokes-length and thefirst string-length, determining whether the computing device isoperated by automatic script executed by said processor.

In some embodiments, the method comprises: monitoring time-intervalsamong the user-side input-unit interactions; based on saidtime-intervals among the user-side input-unit interactions beingconstant, determining that the computing device is operated by anautomatic script executed by said processor.

In some embodiments, the method comprises: monitoring time-intervalsamong the user-side input-unit interactions; modeling human user'stime-intervals among the user-side input-unit interactions; based oncomparing between (A) said monitored time-intervals among the user-sideinput-unit interactions and (B) said modeled human user's time-intervalsamong the user-side input-unit interactions, determining whether thecomputing device is operated by an automatic script executed by saidprocessor.

In some embodiments, the method comprises: monitoring time-gaps amongthe user-side input-unit interactions; determining distribution of saidtime-gaps among the user-side input-unit interactions; if saiddistribution corresponds to a pseudo-random distribution, thendetermining that the computing device is operated by automatic scriptexecuted by said processor.

In some embodiments, the method comprises: monitoring time-gaps amongthe user-side input-unit interactions; storing in a database a userprofile indicating that a particular human user typically types at aparticular temporal pattern of typing when interacting with saidcomputerizes service; subsequently, determining whether a currenttemporal pattern of typing, reflected in a current usage session of saidcomputing device for interacting with said computerized service, isdifferent by at least a threshold percentage from said particulartemporal pattern of typing stored in said user profile; based on saiddetermining, further determining whether the computing device isoperated by automatic script executed by said processor.

In some embodiments, the method comprises: monitoring time-gaps amongthe user-side input-unit interactions; storing in a database a userprofile indicating that a particular human user typically types aparticular sequence of multiple characters in a specific temporalpattern; subsequently, monitoring keystrokes of current user-sideinput-unit interactions; determining whether the current user-sideinput-unit interactions, comprise typing of said particular sequence ofmultiple characters, but do not comprise rapid typing of said particularsequence of multiple characters; based on said determining, furtherdetermining whether the computing device is operated by automatic scriptexecuted by said processor.

In some embodiments, the method comprises: computing a first checksum ofdata entered manually via a keyboard of said computing device; receivingfrom said computerized service a second checksum of user-provided datawhich was transmitted from the computing device to the computerizedservice; matching between (A) the first checksum of data enteredmanually via the keyboard of said computing device, and (B) the secondchecksum of user-provided data which was transmitted from the computingdevice to the computerized service; based on said matching of said firstand second checksums, determining whether the computing device isoperated by automatic script executed by said processor.

In some embodiments, the method comprises: computing a first checksum ofdata entered manually via a keyboard of said computing device; receivingfrom said computerized service a second checksum of user-provided datawhich was transmitted from the computing device to the computerizedservice; matching between (A) the first checksum of data enteredmanually via the keyboard of said computing device, and (B) the secondchecksum of user-provided data which was transmitted from the computingdevice to the computerized service; based on said matching of said firstand second checksums, determining whether the computing device isoperated by automatic script executed by said processor; wherein saiddetermining is performed without receiving from said computerizedservice a copy of said user-provided data which was transmitted from thecomputing device to the computerized service.

In some embodiments, the method comprises: computing a first hashingresult of data entered manually via a keyboard of said computing device;receiving from said computerized service a second hashing result ofuser-provided data which was transmitted from the computing device tothe computerized service; matching between (A) the first hashing resultof data entered manually via the keyboard of said computing device, and(B) the second hashing result of user-provided data which wastransmitted from the computing device to the computerized service; basedon said matching of said first and second hashing results, determiningwhether the computing device is operated by automatic script executed bysaid processor.

In some embodiments, the method comprises: computing a first hashingresult of data entered manually via a keyboard of said computing device;receiving from said computerized service a second hashing result ofuser-provided data which was transmitted from the computing device tothe computerized service; matching between (A) the first hashing resultof data entered manually via the keyboard of said computing device, and(B) the second hashing result of user-provided data which wastransmitted from the computing device to the computerized service; basedon said matching of said first and second hashing results, determiningwhether the computing device is operated by automatic script executed bysaid processor; wherein said determining is performed without receivingfrom said computerized service a copy of said user-provided data whichwas transmitted from the computing device to the computerized service.

In some embodiments, the method comprises: comparing (A) meta-data aboutthe user-side input-unit interactions, with (B) meta-data about the datasent electronically from said computing device to said computerizedservice; wherein the method is performed without receiving from saidcomputerized service a copy of the data sent electronically from saidcomputing device to said computerized service; matching (A) themeta-data about the user-side input-unit interactions, with (B) themeta-data about the data sent electronically from said computing deviceto said computerized service; based on said matching, determiningwhether the computing device is operated by automatic script executed bysaid processor.

In some embodiments, the method comprises: determining that thecomputing device is infected by a code injector malware, by performing:detecting a mismatch between (A) a total number of data fields that thecomputing device transmitted to said computerized service, and (B) atotal number of data fields that the user of the computing devicefilled-out manually via a keyboard of said computing device.

In some embodiments, the method comprises: determining that thecomputing device is infected by a code injector malware, by performing:detecting a mismatch between (A) a total number of data fields that thecomputing device transmitted to said computerized service, and (B) atotal number of strings that the user of the computing device typedmanually via a keyboard of said computing device.

In some embodiments, the method comprises: determining that thecomputing device is infected by a code injector malware, by performing:(a) receiving from said computerized service, meta-data about a numberof filled-out fields that the computerized service receivedelectronically from said computing device; (b) based on monitoreduser-side input-unit interactions, that were manually performed via akeyboard of said computing device, calculating meta-data about a numberof filled-out fields that were manually filled-out via said keyboard;(c) detecting a mismatch between (A) the meta-data about the number offilled-out fields that the computerized service received electronicallyfrom said computing device, and (B) the calculated meta-data about thenumber of filled-out fields that were manually filled-out via saidkeyboard.

In some embodiments, the method comprises: determining that thecomputing device is infected by a code injector malware, by performing:(a) receiving from said computerized service, meta-data about a numberof filled-out fields that the computerized service receivedelectronically from said computing device; (b) based on monitoreduser-side input-unit interactions, that were manually performed via akeyboard of said computing device, calculating meta-data about a numberof filled-out fields that were manually filled-out via said keyboard;(c) detecting a mismatch between (A) the meta-data about the number offilled-out fields that the computerized service received electronicallyfrom said computing device, and (B) the calculated meta-data about thenumber of filled-out fields that were manually filled-out via saidkeyboard; wherein detecting said mismatch is performed withoutreceiving, and without taking into consideration, a copy of the datathat the computerized service received electronically from saidcomputing device.

In some embodiments, the method comprises: based on monitored user-sideinput-unit interactions, computing a particular velocity profile ofpointer strokes; generating a model corresponding to velocity profile ofpointer strokes performed by human users; based on comparison between(A) said particular velocity profile, and (B) said model correspondingto velocity profile of pointer strokes performed by human users,determining whether the computing device is operated by automatic scriptexecuted by said processor.

In some embodiments, the method comprises: based on monitored user-sideinput-unit interactions, extracting a particular time interval profilereflecting time intervals between down click events and up click eventsof a pointing device; generating a model of time intervals between downclick events and up click events of pointing devices performed by humanusers; based on a comparison between (A) said particular time intervalprofile, and (B) said model of time intervals between down-click eventsand up click events of pointing devices performed by human users,determining whether the computing device is operated by automatic scriptexecuted by said processor.

In some embodiments, the method comprises: based on monitored user-sideinput-unit interactions, extracting a profile of time intervals betweenpointer strokes and down click events of a pointing device; generating amodel of time intervals between pointer strokes and down click events ofpointing devices performed by human users; based on comparing between(A) said profile of time intervals, and (B) said model of timeintervals, determining whether the computing device is operated byautomatic script executed by said processor.

In some embodiments, a system comprises: an automatic script detectormodule to determine whether a user, who utilizes a computing device tointeract with a computerized service, is either (i) a human user, or(ii) an automatic script executed by a processor; wherein the automaticscript detector module is: (a) to monitor user-side input-unitinteractions performed through one or more input units; (b) to matchbetween (A) the user-side input-unit interactions and (B) data sentelectronically from said computerized service; (c) if the comparingresult is that (A) the user-side input-unit interactions do not exactlymatch (B) the data sent electronically from said computerized service,then to determine that the computing device is operated by automaticscript executed by said processor.

Some embodiments may detect hardware components and/or hardwareassembly.

In some embodiments, a method comprises: differentiating between (a) afirst hardware assembly utilized for interacting with a computerizedservice, and (b) a second hardware assembly utilized for interactingwith said computerized service, by performing: monitoring user-sideinput-unit interactions of one or more input units which are being usedfor interacting with said computerized service; extracting from saiduser-side input-unit interactions a hardware-assembly-specific usagecharacteristic; performing said differentiating based on saidhardware-assembly-specific usage characteristic.

In some embodiments, the differentiating is independent of, and does nottake into account, data stored in any cookie file on any one of thefirst and second hardware assemblies.

In some embodiments, the differentiating is independent of, and does nottake into account, Internet Protocol (IP) addresses associated with anyone of the first and second hardware assemblies.

In some embodiments, the method comprises: samplingpointing-device-events of said user-side input-unit interactions;determining a device-specific signature reflecting saidpointing-device-events sampling; performing said differentiating basedon said device-specific signature reflecting said pointing-device-eventssampling.

In some embodiments, the method comprises: sampling keyboard-events ofsaid user-side input-unit interactions; determining a device-specificsignature reflecting said keyboard-events sampling; performing saiddifferentiating based on said device-specific signature reflecting saidkeyboard-events sampling.

In some embodiments, the method comprises: sampling touchpad-events ofsaid user-side input-unit interactions; determining a device-specificsignature reflecting said touchpad-events sampling; performing saiddifferentiating based on said device-specific signature reflecting saidtouchpad-events sampling.

In some embodiments, the method comprises: sampling pointing-stickevents of said user-side input-unit interactions; determining adevice-specific signature reflecting said pointing-stick eventssampling; performing said differentiating based on said device-specificsignature reflecting said pointing-stick events sampling.

In some embodiments, the method comprises: measuring a first length of alongest-stroke of on-screen pointer movement, in a first usage sessionof the computerized service; measuring a first length of alongest-stroke of on-screen pointer movement, in a second usage sessionof the computerized service; if the first length of the longest-strokein the first usage session, is different from the second length of thelongest-stroke in the second usage session, by at least a pre-definedpercentage value, then determining that (A) the first usage session ofthe computerized service was accessed via the first hardware assembly,and that (B) the second usage session of the computerized service wasaccessed via the second hardware assembly.

In some embodiments, the method comprises: measuring a first length of alongest-stroke of on-screen pointer movement, in a first usage sessionof the computerized service; measuring a first length of alongest-stroke of on-screen pointer movement, in a second usage sessionof the computerized service; if the first length of the longest-strokein the first usage session, is different from the second length of thelongest-stroke in the second usage session, by at least a pre-definedpercentage value, then determining that (A) the first usage session ofthe computerized service was accessed via a computer mouse, and that (B)the second usage session of the computerized service was accessed via atouchpad.

In some embodiments, the method comprises: analyzing strokes ofmovements of an on-screen pointer movement, in a first usage session ofthe computerized service; analyzing strokes of movements of theon-screen pointer movement, in a second usage session of thecomputerized service; based on both of said analyzing, determining that(A) the first usage session of the computerized service was accessed viaa computer mouse, and that (B) the second usage session of thecomputerized service was accessed via a touchpad.

In some embodiments, the method comprises: analyzing strokes ofmovements of an on-screen pointer movement, in a first usage session ofthe computerized service; analyzing strokes of movements of theon-screen pointer movement, in a second usage session of thecomputerized service; based on both of said analyzing, determining that(A) the first usage session of the computerized service was accessed viaa computer mouse, and that (B) the second usage session of thecomputerized service was accessed via a pointing-stick.

In some embodiments, the method comprises: analyzing strokes ofmovements of an on-screen pointer movement, in a first usage session ofthe computerized service; analyzing strokes of movements of theon-screen pointer movement, in a second usage session of thecomputerized service; based on both of said analyzing, determining that(A) the first usage session of the computerized service was accessed viaa touchpad, and that (B) the second usage session of the computerizedservice was accessed via a pointing-stick.

In some embodiments, the method comprises: measuring acceleration of anon-screen pointer movement, in a first usage session of the computerizedservice; measuring acceleration of an on-screen pointer movement, in asecond usage session of the computerized service; based on both of saidmeasuring, determining that (A) the first usage session of thecomputerized service was accessed via a computer mouse, and that (B) thesecond usage session of the computerized service was accessed via atouchpad.

In some embodiments, the method comprises: measuring acceleration of anon-screen pointer movement, in a first usage session of the computerizedservice; measuring acceleration of an on-screen pointer movement, in asecond usage session of the computerized service; based on both of saidmeasuring, determining that (A) the first usage session of thecomputerized service was accessed via a computer mouse, and that (B) thesecond usage session of the computerized service was accessed via apointing-stick.

In some embodiments, the method comprises: measuring acceleration of anon-screen pointer movement, in a first usage session of the computerizedservice; measuring acceleration of an on-screen pointer movement, in asecond usage session of the computerized service; based on both of saidmeasuring, determining that (A) the first usage session of thecomputerized service was accessed via a touchpad, and that (B) thesecond usage session of the computerized service was accessed via apointing-stick.

In some embodiments, the method comprises: sampling and analyzingmouse-events in a first usage session of the computerized service;sampling and analyzing mouse-events in a second usage session of thecomputerized service; based on differences between (a) the sampled andanalyzed mouse events in the first usage session, and (b) the sampledand analyzed mouse events in the second usage session, determining that(A) the first usage session was accessed via a first mouse-device madeby a first manufacturer, and that (B) the second usage session wasaccessed via a second mouse-device made by a second manufacturer.

In some embodiments, the method comprises: sampling and analyzingmouse-events in a first usage session of the computerized service;sampling and analyzing mouse-events in a second usage session of thecomputerized service; based on differences between (a) the sampled andanalyzed mouse events in the first usage session, and (b) the sampledand analyzed mouse events in the second usage session, determining that(A) the first usage session was accessed via a first mouse-device madeby a particular manufacturer and having a particular model number, andthat (B) the second usage session was accessed via a second mouse-devicemade by the same particular manufacturer and having the same particularmodel number.

In some embodiments, the method comprises: temporarily generating aresource-consuming burden on client-side hardware assemblies that areused for accessing said computerized service; measuring performance ofmultiple client-side hardware assemblies in response to the generatedresource-consuming burden; based on the measured performance of multipleclient-side hardware assemblies in response to the generatedresource-consuming burden, differentiating between said first hardwareassembly and said second hardware assembly.

In some embodiments, the method comprises: temporarily generating acomputation-intensive burden on client-side hardware assemblies that areused for accessing said computerized service; measuring performance ofmultiple client-side hardware assemblies in response to the generatedcomputation-intensive burden; based on the measured performance ofmultiple client-side hardware assemblies in response to the generatedcomputation-intensive burden, differentiating between said firsthardware assembly and said second hardware assembly.

In some embodiments, the method comprises: monitoring keyboardinteractions with said computerized service; identifying a sequence ofmultiple particular characters, that are entered consecutively viakeyboard more rapidly than other character sequences; determining thatsaid sequence of multiple characters, is more common in a particularnatural language; determining that said computerized service is accessedvia a hardware assembly utilizing a keyboard having a keyboard-layout ofsaid particular natural language.

In some embodiments, the method comprises: monitoring keyboardinteractions with said computerized service; identifying a sequence ofmultiple particular characters, that are entered consecutively viakeyboard more rapidly than other character sequences; determining thatsaid sequence of multiple characters, is more common in a particularnatural language; determining that said computerized service is accessedvia a hardware assembly utilizing a keyboard having a keyboard-layout ofsaid particular natural language; wherein both of said determiningoperations are performed without taking into consideration an InternetProtocol (IP) address associated with said hardware assembly being usedfor accessing said computerized service.

In some embodiments, the method comprises: displaying through saidcomputerized service a challenge requesting a user to correctly enter aparticular word in a particular non-English natural language, whereintyping of the particular word requires typing an accented character;receiving user-entered keystrokes which indicate typing of saidparticular word while typing said accented character; based on saiduser-entered keystrokes which indicate typing of said particular wordwhile typing said accented character, determining that the computerizedservice is accessed by a user that utilizes a keyboard having anon-English keyboard layout which corresponds to said particularnon-English natural language.

In some embodiments, the method comprises: displaying through saidcomputerized service a challenge requesting a user to correctly enter aparticular word in a particular non-English natural language, whereintyping of the particular word requires typing a character having adiacritical mark; receiving user-entered keystrokes which indicatetyping of said particular word while typing said character having saiddiacritical mark; based on said user-entered keystrokes which indicatetyping of said particular word while typing said character having saiddiacritical mark, determining that the computerized service is accessedby a user that utilizes a keyboard having a non-English keyboard layoutwhich corresponds to said particular non-English natural language.

In some embodiments, a system comprises a hardware assembly detectormodule to differentiate between (a) a first hardware assembly utilizedfor interacting with a computerized service, and (b) a second hardwareassembly utilized for interacting with said computerized service;wherein the hardware assembly detector module is: to monitor user-sideinput-unit interactions of one or more input units which are being usedfor interacting with said computerized service; to extract from saiduser-side input-unit interactions a hardware-assembly-specific usagecharacteristic; to perform differentiation based on saidhardware-assembly-specific usage characteristic.

Some embodiments may enable user segmentation based on monitoring ofinput-unit interactions.

In some embodiments, a method comprises: differentiating between (a) afirst user interacting with a computerized service, and (b) a seconduser interacting with said computerized service; wherein thedifferentiating does not rely on Internet Protocol (IP) addressanalysis; wherein the differentiating does not rely on cookie filesanalysis; wherein the differentiating comprises: monitoring user-sideinput-unit interactions with said computerized service; extracting fromsaid user-side input-unit interactions a user-specific characteristic;based on the user-specific characteristic extracted from said user-sideinput-unit interactions, differentiating between said first user andsaid second user.

In some embodiments, the differentiating (A) does not rely on injectionof a user-interface interference to said computerized service, and (B)does not rely on user reaction to any user-interface interference.

In some embodiments, the extracting comprises: extracting from saiduser-side input-unit interactions a user-specific characteristic whichindicates at least one of: (a) user gender; (b) user age-range; (c) usergeographic location; (d) user level of expertise in computer-relatedtasks; (e) user anatomical characteristics.

In some embodiments, the method comprises: monitoring utilization ofkeyboard shortcuts during interactions with said computerized service;based on the monitored utilization of keyboard shortcuts duringinteractions with said computerized service, determining the level ofexpertise of a particular user in operating computerized platforms.

In some embodiments, the method comprises: monitoring utilization ofkeyboard shortcuts during interactions with said computerized service;based on the monitored utilization of keyboard shortcuts duringinteractions with said computerized service, determining whether aparticular user is (a) within an age-range of 15 to 30 years old, or (b)within an age-range of 65 and greater years old.

In some embodiments, the method comprises: monitoring utilization ofcopy-and-paste operations during interactions with said computerizedservice; based on the monitored utilization of copy-and-paste operationsduring interactions with said computerized service, determining thelevel of expertise of a particular user in operating computerizedplatforms

In some embodiments, the method comprises: monitoring average typingspeed during interactions with said computerized service; based on themonitored average typing speed during interactions with saidcomputerized service, determining the level of expertise of a particularuser in operating computerized platforms.

In some embodiments, the method comprises: monitoring average typingspeed during interactions with said computerized service; based on themonitored average typing speed during interactions with saidcomputerized service, determining whether a particular user is an olduser or a young user.

In some embodiments, the method comprises: monitoring user keystrokesduring interactions with said computerized service; extractingstatistics of time-gaps between pairs of key-down and key-up events;based on the extracted statistics of said time-gaps between pairs ofkey-down and key-up events, determining whether a particular user is amale user or a female user.

In some embodiments, the method comprises: monitoring keyboardinteractions of a user with said computerized service; extractingstatistics of time-gaps between pairs of key-down and key-up events, forkeys in different locations along the keyboard; based on the extractedstatistics of time-gaps, determining whether the fingers of a particularuser are short or long.

In some embodiments, the method comprises: monitoring keystrokes of afirst user during interactions with said computerized service;extracting first statistics of the time-gaps between pairs of key-downand key-up events during the first user interactions with thecomputerized service; monitoring keystrokes of a second user duringinteractions with said computerized service; extracting secondstatistics of the time-gaps between pairs of key-down and key-up eventsduring the second user interactions with the computerized service; basedon said extracted first statistics of first user and said extractedsecond statistics of second user, differentiating that the first user ismale and that the second user is female.

In some embodiments, the method comprises: monitoring keyboardinteractions of a first user with said computerized service; identifyinga sequence of multiple particular characters, that are entered by thefirst user consecutively via keyboard more rapidly than other charactersequences that the first user types; determining that said sequence ofmultiple characters, is more common in a particular natural language;determining that keyboard interactions of a second user, with saidcomputerized service, lack rapid typing of said sequence of particularcharacters; based on both of said determining, differentiating betweenthe first user and the second user.

In some embodiments, the method comprises: monitoring keyboardinteractions of a first user with said computerized service; identifyinga sequence of multiple particular characters, that are entered by thefirst user consecutively via keyboard more rapidly than other charactersequences that the first user types; determining that said sequence ofmultiple characters, is more common for users of a particular keyboardlayout that is more common at a particular geographic region;determining that keyboard interactions of a second user, with saidcomputerized service, lack rapid typing of said sequence of particularcharacters; based on both of said determining, differentiating betweenthe first user and the second user.

In some embodiments, the method comprises: sampling user-side input-unitinteractions of a user with said computerized service; performingfrequency analysis of said sampled user-side input-unit interactions ofa first user with said computerized service; based on said frequencyanalysis, determining characteristics of a power supply of the computingdevice of said user; based on determinations of characteristics of thepower supply of the computing device of said user, determining that thecomputing device of said user is located in a particular geographicregion.

In some embodiments, the method comprises: monitoring keyboardinteractions of a first user with said computerized service; based oncharacteristics of the monitored keyboard interactions, determining both(A) gender of the first user, and (B) age-range of said user; based onthe determined gender and age-range of said first user, displaying tosaid first user tailored advertisement content.

In some embodiments, the method comprises: monitoring keyboardinteractions of a first user with said computerized service; based oncharacteristics of the monitored keyboard interactions, determining both(A) a natural language spoken by the first user, and (B) age-range ofsaid user; based on the determined natural language and age-range ofsaid first user, displaying to said first user tailored advertisementcontent.

In some embodiments, the method comprises: monitoring user-sideinput-unit interactions of the first user with said computerizedservice; based on characteristics of the monitored keyboard interactionsand pointing device events, determining a current mood of said user;based on the determined mood of said first user, displaying to saidfirst user tailored content suitable for said current mood of said firstuser.

In some embodiments, a system comprises: a user identity determinationmodule to differentiate between (a) a first user interacting with acomputerized service, and (b) a second user interacting with saidcomputerized service; wherein the differentiating by the user identitydetermination module does not rely on Internet Protocol (IP) addressanalysis; wherein the differentiating by the user identity determinationmodule does not rely on cookie files analysis;

wherein the user identity determination module is: to monitor user-sideinput-unit interactions with said computerized service; to extract fromsaid user-side input-unit interactions a user-specific characteristic;based on the user-specific characteristic extracted from said user-sideinput-unit interactions, to differentiate between said first user andsaid second user.

In some embodiments, the system comprises: a user expertise estimatormodule (A) to monitor utilization of keyboard shortcuts duringinteractions with said computerized service, and (B) based on themonitored utilization of keyboard shortcuts during interactions withsaid computerized service, determining the level of expertise of aparticular user in operating computerized platforms.

In some embodiments, the system comprises: a user gender estimatormodule (a) to monitor user keystrokes during interactions with saidcomputerized service, (b) to extract statistics of time-gaps betweenpairs of key-down and key-up events, and (c) based on the extractedstatistics of said time-gaps between pairs of key-down and key-upevents, to determine whether a particular user is a male user or afemale user.

Some embodiments may identify multiple-users accessing the same account(e.g., subscription account, personal account).

In some embodiments, a method comprises: determining that a particularsubscription account of a computerized service, is accessed by twodifferent human users who utilize a same set of login credentials, byperforming: (a) monitoring input-unit interactions of pairs of usagesessions that originated from pairs of two different subscriptionsaccounts; (b) extracting from the input-unit interactions that weremonitored in step (a), a cross-account usage-session pairing pattern;(c) monitoring input-unit interactions of pairs of usage sessions thatoriginated from a same subscription account; (d) extracting from theinput-unit interactions that were monitored in step (c), anintra-account usage-session pairing pattern; (e) determining whether apair of usage sessions, that originated from said particularsubscription account, is: (i) relatively more similar to thecross-account usage-session pairing pattern, or (ii) relatively moresimilar to the intra-account usage-session pairing pattern.

In some embodiments, the method comprises: if it is determined in step(e) that the pair of usage session, that originated from said particularsubscription account, is relatively more similar to the cross-accountusage-session pairing pattern, then generating a notification that saidparticular subscription account is accessed by two different human userswho utilize the same set of login credentials.

In some embodiments, the monitoring of step (a) comprises: monitoringinput-unit interactions of pairs of usage sessions that originated frompairs of two different subscriptions accounts and which comprise userreactions to an injected user-interface interference; wherein themonitoring of step (c) comprises: monitoring input-unit interactions ofpairs of usage sessions that originated from a same subscription accountand which comprise user reactions to said injected user-interfaceinterference.

In some embodiments, the monitoring of step (a) comprises: monitoringinput-unit interactions of pairs of usage sessions that originated frompairs of two different subscriptions accounts and which comprise naturalinteractions that are not induced by any user-interface interference;wherein the monitoring of step (c) comprises: monitoring input-unitinteractions of pairs of usage sessions that originated from a samesubscription account and which comprise natural interactions that arenot induced by any user-interface interference.

In some embodiments, the method comprises: checking whether acharacteristic of monitored user-interface interactions over a pair ofusage-sessions of a same subscription account, is more similar toeither: (i) a first pattern of user-interface interactions thatcharacterize multiple pairs of usage sessions of different human users,or (ii) a second pattern of user-interface interactions thatcharacterizes multiple pairs of usage sessions wherein each pair ofusage session belong to the same subscription account.

In some embodiments, the method comprises: if it is determined that saidcharacteristic of monitored user-interface interactions, over said pairof usage-sessions of the same subscription account, is more similar tosaid first pattern of user-interface interactions that characterizemultiple pairs of usage sessions of different human users, thengenerating a notification that said particular subscription account isaccessed by two different human users who utilize the same set of logincredentials.

In some embodiments, the method comprises: checking whether acharacteristic of monitored user-interface interactions over a pair ofusage-sessions of a same subscription account, that comprise userreactions to an injected user-interface interference, is more similar toeither: (i) a first pattern of user-interface interactions thatcharacterize multiple pairs of usage sessions of different human users,or (ii) a second pattern of user-interface interactions thatcharacterizes multiple pairs of usage sessions wherein each pair ofusage session belong to the same subscription account.

In some embodiments, the method comprises: if it is determined that saidcharacteristic of monitored user-interface interactions, over said pairof usage-sessions of the same subscription account, that comprise userreactions to said injected user-interface interference, is more similarto said first pattern of user-interface interactions that characterizemultiple pairs of usage sessions of different human users, thengenerating a notification that said particular subscription account isaccessed by two different human users who utilize the same set of logincredentials.

In some embodiments, the computerized service comprises a serviceselected from the group consisting of: a digital streaming videoservice; a digital streaming audio service; an online gaming service.

In some embodiments, the computerized service comprises a serviceselected from the group consisting of: an online premium-content serviceavailable only to paying subscribers; an online legal informationservice available only to paying subscribers; an online financialinformation service available only to paying subscribers; an onlinebusiness information service available only to paying subscribers; anonline news information service available only to paying subscribers.

In some embodiments, the method comprises: generating an attributesvector for each usage session; utilizing a clustering algorithm todetermine the number of most-probable sources for the usage sessions;based on the clustering result, determining whether the usage sessionscorrespond to one use or to multiple users.

In some embodiments, the method comprises: generating an ad-hoc modelreflecting user-side interactions that were performed in all usagesessions that originated from a particular computing device; based onsaid ad-hoc model, for all other usage sessions accesses using adifferent device, comparing said usage sessions to said model; if aparticular usage session is determined to be significantly differentthan said ad-hoc model, then determining the said particular usagesession originated from a different user.

In some embodiments, a method comprises: determining that a particularsubscription account of a computerized service, is accessed by two ormore different human users who utilize a same set of login credentials,by performing: (a) monitoring input-unit interactions of sets ofmultiple usage sessions that originated from sets of multiple differentsubscriptions accounts; (b) extracting from the input-unit interactionsthat were monitored in step (a), a cross-account usage-session groupingpattern; (c) monitoring input-unit interactions of sets of usagesessions that originated from a same subscription account; (d)extracting from the input-unit interactions that were monitored in step(c), an intra-account usage-session grouping pattern; (e) determiningwhether a set of multiple usage sessions, that originated from saidparticular subscription account, is: (i) relatively more similar to thecross-account usage-session grouping pattern, or (ii) relatively moresimilar to the intra-account usage-session grouping pattern.

In some embodiments, each one of the sets of multiple usage sessionscomprise a pair of usage sessions.

In some embodiments, each one of the sets of multiple usage sessionscomprise a set of three usage sessions.

In some embodiments, each one of the sets of multiple usage sessionscomprise a group of four usage sessions.

In some embodiments, a system comprises: a multiple-users for sameaccount detector, to determine that a particular subscription account ofa computerized service, is accessed by two different human users whoutilize a same set of login credentials; wherein the multiple-users forsame account detector is: (a) to monitor input-unit interactions ofpairs of usage sessions that originated from pairs of two differentsubscriptions accounts; (b) to extract from the input-unit interactionsthat were monitored in step (a), a cross-account usage-session pairingpattern; (c) to monitor input-unit interactions of pairs of usagesessions that originated from a same subscription account; (d) toextract from the input-unit interactions that were monitored in step(c), an intra-account usage-session pairing pattern; (e) to determinewhether a pair of usage sessions, that originated from said particularsubscription account, is: (i) relatively more similar to thecross-account usage-session pairing pattern, or (ii) relatively moresimilar to the intra-account usage-session pairing pattern.

In some embodiments, if it is determined in step (e) that the pair ofusage session, that originated from said particular subscriptionaccount, is relatively more similar to the cross-account usage-sessionpairing pattern, then the multiple-users for same account detector is togenerate a notification that said particular subscription account isaccessed by two different human users who utilize the same set of logincredentials.

In some embodiments, in step (a), the multiple-users for same accountdetector is to monitor input-unit interactions of pairs of usagesessions that originated from pairs of two different subscriptionsaccounts and which comprise user reactions to an injected user-interfaceinterference; wherein in step (c), the multiple-users for same accountdetector is to monitor input-unit interactions of pairs of usagesessions that originated from a same subscription account and whichcomprise user reactions to said injected user-interface interference.

In some embodiments, the multiple-users for same account detector is todetermine that a particular subscription account of a computerizedservice, is accessed by two or more different human users who utilize asame set of login credentials, by performing: (a) monitoring input-unitinteractions of sets of multiple usage sessions that originated fromsets of multiple different subscriptions accounts; (b) extracting fromthe input-unit interactions that were monitored in step (a), across-account usage-session grouping pattern; (c) monitoring input-unitinteractions of sets of usage sessions that originated from a samesubscription account; (d) extracting from the input-unit interactionsthat were monitored in step (c), an intra-account usage-session groupingpattern; (e) determining whether a set of multiple usage sessions, thatoriginated from said particular subscription account, is: (i) relativelymore similar to the cross-account usage-session grouping pattern, or(ii) relatively more similar to the intra-account usage-session groupingpattern.

Some embodiments may enable a visual login process, as well as animplicit two-factor authentication (TFA) process, and stochasticcryptography based on monitored user-side input-unit interactions.

In some embodiments, a method comprises: differentiating between a firstuser and a second user of a computerized service, by performing:presenting an on-screen visual login interface which requires a user ofthe computerized service to interact with user interface elements inorder to enter user login credentials for said computerized service;monitoring interactions of said used via an input unit with said userinterface elements of said on-screen visual login interface; extractingfrom said interaction of the user via the input unit, a user-specifictrait indicating a user-specific manner of interaction with saidon-screen visual login interface; based on the extracted user-specificmanner of interaction, differentiating between a first user and a seconduser of said computerized service.

In some embodiments, the presenting comprises: presenting an on-screenkeypad of digits, and an on-screen target zone; generating adrag-and-drop interface that allows the user to selectively dragindividual digits, which correspond to a Personal Identification Number(PIN) that the user desires to enter, from said on-screen keypad to saidon-screen target zone; wherein the monitoring of interactions comprises:monitoring a manner in which the user performs drag-and-drop operationsof said individual digits, and extracting a user-specific trait fromsaid drag-and-drop operations of individual digits.

In some embodiments, the presenting comprises: presenting an on-screenvault interface having one or more on-screen cylinders; generating anon-screen interface that allows the user to selectively rotate the oneor more on-screen rotatable cylinders in order to input a PersonalIdentification Number (PIN) that the user desires to enter; wherein themonitoring of interactions comprises: monitoring a manner in which theuser performs rotations of the one or more on-screen rotatablecylinders, and extracting a user-specific trait from said rotations.

In some embodiments, the method comprises: injecting a user interfaceinterference to an operation of said user interface elements; monitoringa corrective reaction of the user to the injected user interfaceinterference; extracting a user-specific trait corresponding to saidcorrective reaction; based on the user-specific trait corresponding tosaid corrective reaction, differentiating between the first user and thesecond user of said computerized service.

In some embodiments, the presenting comprises: presenting an on-screenkeypad of digits, and an on-screen target zone; generating adrag-and-drop interface that allows the user to selectively dragindividual digits, which correspond to a Personal Identification Number(PIN) that the user desires to enter, from said on-screen keypad to saidon-screen target zone; wherein injecting the user interface interferencecomprises: injecting a user interface interference to an operation ofsaid drag-and-drop interface; wherein the monitoring of interactionscomprises: monitoring a manner in which the user reacts to the injecteduser-interface interference to the operation of said drag-and-dropinterface, and extracting a user-specific trait from the correctivereaction of the user.

In some embodiments, the presenting comprises: presenting an on-screenvault interface having one or more on-screen cylinders; generating anon-screen interface that allows the user to selectively rotate the oneor more on-screen rotatable cylinders in order to input a PersonalIdentification Number (PIN) that the user desires to enter; whereininjecting the user interface interference comprises: injecting a userinterface interference to an operation of said rotatable cylinders;wherein the monitoring of interactions comprises: monitoring a manner inwhich the user reacts to the injected user-interface interference to theoperation of said on-screen rotatable cylinders, and extracting auser-specific trait from the corrective reaction of the user.

In some embodiments, the injected user-interface interference causes anon-screen pointer to be non-responsive for a pre-defined period of time.

In some embodiments, the injected user-interface interference causes anon-screen pointer to move in a route that is non-identical to a movementroute of said input unit.

In some embodiments, the method comprises: presenting an on-screencollection of items; presenting to the user a textual notification thatthe user is required to select a particular item from said collection,wherein the textual notification comprise a textual instruction in anatural language that a human user is required to comprehend in order tocorrectly select said particular item from said collection; introducingan interference to a drag-and-drop operation of said particular item;checking whether a current reaction of the user to said interference,matches a user-specific profile of said user indicating past reactionsof said user to said interference.

In some embodiments, the method comprises: presenting an on-screenjigsaw puzzle as part of a login process; monitoring a manner in whichthe user solves the on-screen jigsaw puzzle; extracting a user-specificprofile corresponding to the manner in which the user solves theon-screen jigsaw puzzle; in a subsequent login process, checking whether(a) a current manner of the user solving the on-screen jigsaw puzzle,matches (b) the user-specific profile corresponding to the manner inwhich the user solved the on-screen jigsaw puzzle in previous loginsessions.

In some embodiments, the method comprises: during a log-in process andwhile the user enters user credentials through a mobile computingdevice, injecting a time-delay between (A) tapping of a character on anon-screen keyboard by the user, and (B) displaying said character on thescreen of the mobile computing device; monitoring user reactions to theinjected time-delay between tapping and displaying; extracting auser-specific profile reflecting a typical reaction of said user toinjected time-delays between tapping and displaying; in a subsequentlog-in session, checking whether (i) a current reaction of the user totime-delay between tapping and displaying, matches (ii) theuser-specific profile reflecting the typical reaction of said user toinjected time-delays between tapping and displaying.

In some embodiments, the method comprises: during a log-in process,causing an Enter key to be non-responsive to keystrokes; presenting anon-screen Submit button; introducing an on-screen interference toregular operation of said on-screen Submit button; monitoring userreactions to the on-screen interference to the regular operation of saidon-screen Submit button; extracting a user-specific profile reflecting atypical reaction of said user to the on-screen interference to theregular operation of said on-screen Submit button; in a subsequentlog-in session, checking whether (i) a current reaction of the user tothe on-screen interference to the regular operation of the on-screenSubmit button, matches (ii) the user-specific profile reflecting thetypical reaction of said user to the on-screen interference to theregular operation of the on-screen Submit button.

In some embodiments, the method comprises: performing an implicittwo-factor authentication process as a condition for authorizing saiduser to access said computerized service, wherein a first-step of theimplicit two-factor authentication process comprises receiving from theuser a correct value of a password previously-defined by said user;wherein a second-step of the implicit two-factor authentication processcomprises receiving from said user said correct value in an input mannerthat exhibits a particular user-specific trait that had been extractedfrom previous input-unit interactions of said user.

In some embodiments, the method comprises: performing an implicittwo-factor authentication process as a condition for authorizing saiduser to access said computerized service, wherein a first-step of theimplicit two-factor authentication process comprises receiving from theuser a correct value of a password previously-defined by said user;wherein a second-step of the implicit two-factor authentication processcomprises: injecting a user interface interference to an interfacepresented to said user; and receiving from said user said correct valuein an input manner which reacts to said interference and which exhibitsa particular user-specific trait that had been extracted from previousinput-unit interactions of said user in response to said interference.

In some embodiments, the method comprises: presenting to the user, oneinterference at a time, a sequence of user-interface interferences thatare selected one at a time from a pool of possible user-interfaceinterferences; monitoring user reactions to the user-interfaceinterferences that were presented to the user, one interference at atime; generating a user-specific general reaction model that reflects ageneral manner of reactions to user-interface interferences by saiduser; generating an encryption key by using a parameter of saiduser-specific general reaction model; encrypting a content item of saiduser by using said encryption key that was generated based on saiduser-specific general reaction model.

In some embodiments, the method comprises: upon a user request todecrypt said content item, performing: presenting to the user a singleuser-interface interference, from the sequence of user-interfaceinterferences that were selected and used for generating theuser-specific general reaction model prior to said encrypting step;monitoring a current reaction of said user to the single user-interfaceinterference that is presented to the user; extracting a user-specificvalue from the current reaction of said user to the singleuser-interface interference that is presented to the user; calculating adecryption key based on the user-specific value that was extracted fromthe current reaction of said user to the single user-interfaceinterference that is presented to the user; decrypting said content itemby using said decryption key.

In some embodiments, said sequence of user-interface interferencecomprise a sequence of at least 20 user-interface interferences, thatare selected one-at-a-time from a pool comprising at least 100user-interface interferences.

In some embodiments, the method comprises: performing stochasticencryption of a content item associated with said user, by utilizing anencryption key that is based, at least partially, on a user-specificmodel that reflects a general manner in which said user responds to atleast 10 different user-interface interferences.

In some embodiments, the method comprises: performing stochasticencryption of a content item associated with said user, by utilizing anencryption key that is based, at least partially, on a user-specificmodel that reflects a general manner in which said user responds to aseries of at least 10 different user-interface interferences that werepresented to said user one interference at a time; performing stochasticdecryption of said content item associated with said user, by utilizinga decryption key that is based, at least partially, on a single reactionof said user to a single user-interface interference that is presentedto said user in response to a user request to decrypt said content item.

In some embodiments, the method comprises: performing a stochasticcryptography operation which utilizes, as a cryptographic parameter, avalue of a user-specific model of reaction to a user interfaceinterference of a particular type.

In some embodiments, the method comprises: injecting a user interfaceinterference to an interaction of said user with said computerizedservice; monitoring user reaction to said user interface interference;extracting a user-specific interference-specific parameter whichindicates an attribute of the user reaction to said user interfaceinterference; performing a stochastic cryptography operation whichutilizes, as a cryptographic parameter, a value of said user-specificinterference-specific parameter which indicates said attribute of theuser reaction to said user interface interference.

In some embodiments, the method comprises: estimating a false positivemargin-of-error of said stochastic cryptography operation; allowing theuser to perform multiple access attempts to compensate for the estimatedfalse positive margin-of-error of said stochastic cryptographyoperation.

In some embodiments, the stochastic cryptography operation comprises atleast one of: encryption, decryption.

In some embodiments, the cryptographic parameter comprises: a value ofsaid user-specific interference-specific parameter which indicates saidattribute of the user reaction to said user interface interference whichis introduced during said visual login process.

In some embodiments, a system comprises: a visual login module todifferentiate between a first user and a second user of a computerizedservice, wherein the visual login module is: to present an on-screenvisual login interface which requires a user of the computerized serviceto interact with user interface elements in order to enter user logincredentials for said computerized service; to monitor interactions ofsaid used via an input unit with said user interface elements of saidon-screen visual login interface; to extract from said interaction ofthe user via the input unit, a user-specific trait indicating auser-specific manner of interaction with said on-screen visual logininterface; based on the extracted user-specific manner of interaction,to differentiate between a first user and a second user of saidcomputerized service.

In some embodiments, the visual login module is to perform an implicittwo-factor authentication process as a condition for authorizing saiduser to access said computerized device, wherein a first-step of theimplicit two-factor authentication process comprises receiving from theuser a correct value of a password previously-defined by said user;wherein a second-step of the implicit two-factor authentication processcomprises receiving from said user said correct value in an input mannerthat exhibits a particular user-specific trait that had been extractedfrom previous input-unit interactions of said user.

In some embodiments, the system comprises a stochastic cryptographymodule, wherein the stochastic cryptography module is: to inject a userinterface interference to an interaction of said user with saidcomputerized service; to monitor user reaction to said user interfaceinterference; to extract a user-specific interference-specific parameterwhich indicates an attribute of the user reaction to said user interfaceinterference; to perform a stochastic cryptography operation whichutilizes, as a cryptographic parameter, a value of said user-specificinterference-specific parameter which indicates said attribute of theuser reaction to said user interface interference.

Although portions of the discussion herein relate, for demonstrativepurposes, to wired links and/or wired communications, some embodimentsof the present invention are not limited in this regard, and may includeone or more wired or wireless links, may utilize one or more componentsof wireless communication, may utilize one or more methods or protocolsof wireless communication, or the like. Some embodiments may utilizewired communication and/or wireless communication.

Functions, operations, components and/or features described herein withreference to one or more embodiments of the present invention, may becombined with, or may be utilized in combination with, one or more otherfunctions, operations, components and/or features described herein withreference to one or more other embodiments of the present invention.

While certain features of the present invention have been illustratedand described herein, many modifications, substitutions, changes, andequivalents may occur to those skilled in the art. Accordingly, theclaims are intended to cover all such modifications, substitutions,changes, and equivalents.

What is claimed is:
 1. A method comprising: differentiating between afirst user and a second user of a computerized service, by performing:presenting an on-screen visual login interface which requires a user ofthe computerized service to interact with user interface elements inorder to enter user login credentials for said computerized service;monitoring interactions of said used via an input unit with said userinterface elements of said on-screen visual login interface; extractingfrom said interaction of the user via the input unit, a user-specifictrait indicating a user-specific manner of interaction with saidon-screen visual login interface; based on the extracted user-specificmanner of interaction, differentiating between a first user and a seconduser of said computerized service; wherein the presenting comprises:presenting an on-screen vault interface having one or more on-screencylinders; and generating an on-screen interface that allows the user toselectively rotate the one or more on-screen rotatable cylinders inorder to input a Personal Identification Number (PIN) that the userdesires to enter; wherein the monitoring of interactions comprises:monitoring a manner in which the user performs rotations of the one ormore on-screen rotatable cylinders, and extracting a user-specific traitfrom said rotations.
 2. The method of claim 1, wherein the presentingcomprises: presenting an on-screen keypad of digits, and an on-screentarget zone; generating a drag-and-drop interface that allows the userto selectively drag individual digits, which correspond to a PersonalIdentification Number (PIN) that the user desires to enter, from saidon-screen keypad to said on-screen target zone; wherein the monitoringof interactions comprises: monitoring a manner in which the userperforms drag-and-drop operations of said individual digits, andextracting a user-specific trait from said drag-and-drop operations ofindividual digits.
 3. A method comprising: differentiating between afirst user and a second user of a computerized service, by performing:presenting an on-screen visual login interface which requires a user ofthe computerized service to interact with user interface elements inorder to enter user login credentials for said computerized service;monitoring interactions of said used via an input unit with said userinterface elements of said on-screen visual login interface; extractingfrom said interaction of the user via the input unit, a user-specifictrait indicating a user-specific manner of interaction with saidon-screen visual login interface; based on the extracted user-specificmanner of interaction, differentiating between a first user and a seconduser of said computerized service; wherein the method comprises:injecting a user interface interference to an operation of said userinterface elements; monitoring a corrective reaction of the user to theinjected user interface interference; extracting a user-specific traitcorresponding to said corrective reaction; based on the user-specifictrait corresponding to said corrective reaction, differentiating betweenthe first user and the second user of said computerized service; whereinthe presenting comprises: presenting an on-screen vault interface havingone or more on-screen cylinders; and generating an on-screen interfacethat allows the user to selectively rotate the one or more on-screenrotatable cylinders in order to input a Personal Identification Number(PIN) that the user desires to enter; wherein injecting the userinterface interference comprises: injecting a user interfaceinterference to an operation of said rotatable cylinders; wherein themonitoring of interactions comprises: monitoring a manner in which theuser reacts to the injected user-interface interference to the operationof said on-screen rotatable cylinders, and extracting a user-specifictrait from the corrective reaction of the user.
 4. The method of claim3, wherein the presenting comprises: presenting an on-screen keypad ofdigits, and an on-screen target zone; generating a drag-and-dropinterface that allows the user to selectively drag individual digits,which correspond to a Personal Identification Number (PIN) that the userdesires to enter, from said on-screen keypad to said on-screen targetzone; wherein injecting the user interface interference comprises:injecting a user interface interference to an operation of saiddrag-and-drop interface; wherein the monitoring of interactionscomprises: monitoring a manner in which the user reacts to the injecteduser-interface interference to the operation of said drag-and-dropinterface, and extracting a user-specific trait from the correctivereaction of the user.
 5. The method of claim 3, wherein the injecteduser-interface interference causes an on-screen pointer to benon-responsive for a pre-defined period of time.
 6. The method of claim3, wherein the injected user-interface interference causes an on-screenpointer to move in a route that is non-identical to a movement route ofsaid input unit.
 7. The method of claim 1, comprising: presenting anon-screen collection of items; presenting to the user a textualnotification that the user is required to select a particular item fromsaid collection, wherein the textual notification comprise a textualinstruction in a natural language that a human user is required tocomprehend in order to correctly select said particular item from saidcollection; introducing an interference to a drag-and-drop operation ofsaid particular item; checking whether a current reaction of the user tosaid interference, matches a user-specific profile of said userindicating past reactions of said user to said interference.
 8. Themethod of claim 1, comprising: presenting an on-screen jigsaw puzzle aspart of a login process; monitoring a manner in which the user solvesthe on-screen jigsaw puzzle; extracting a user-specific profilecorresponding to the manner in which the user solves the on-screenjigsaw puzzle; in a subsequent login process, checking whether (a) acurrent manner of the user solving the on-screen jigsaw puzzle, matches(b) the user-specific profile corresponding to the manner in which theuser solved the on-screen jigsaw puzzle in previous login sessions. 9.The method of claim 1, comprising: during a log-in process and while theuser enters user credentials through a mobile computing device,injecting a time-delay between (A) tapping of a character on anon-screen keyboard by the user, and (B) displaying said character on thescreen of the mobile computing device; monitoring user reactions to theinjected time-delay between tapping and displaying; extracting auser-specific profile reflecting a typical reaction of said user toinjected time-delays between tapping and displaying; in a subsequentlog-in session, checking whether (i) a current reaction of the user totime-delay between tapping and displaying, matches (ii) theuser-specific profile reflecting the typical reaction of said user toinjected time-delays between tapping and displaying.
 10. The method ofclaim 1, comprising: during a log-in process, causing an Enter key to benon-responsive to keystrokes; presenting an on-screen Submit button;introducing an on-screen interference to regular operation of saidon-screen Submit button; monitoring user reactions to the on-screeninterference to the regular operation of said on-screen Submit button;extracting a user-specific profile reflecting a typical reaction of saiduser to the on-screen interference to the regular operation of saidon-screen Submit button; in a subsequent log-in session, checkingwhether (i) a current reaction of the user to the on-screen interferenceto the regular operation of the on-screen Submit button, matches (ii)the user-specific profile reflecting the typical reaction of said userto the on-screen interference to the regular operation of the on-screenSubmit button.
 11. The method of claim 1, comprising: performing animplicit two-factor authentication process as a condition forauthorizing said user to access said computerized device, wherein afirst-step of the implicit two-factor authentication process comprisesreceiving from the user a correct value of a password previously-definedby said user; wherein a second-step of the implicit two-factorauthentication process comprises receiving from said user said correctvalue in an input manner that exhibits a particular user-specific traitthat had been extracted from previous input-unit interactions of saiduser.
 12. The method of claim 1, comprising: performing an implicittwo-factor authentication process as a condition for authorizing saiduser to access said computerized device, wherein a first-step of theimplicit two-factor authentication process comprises receiving from theuser a correct value of a password previously-defined by said user;wherein a second-step of the implicit two-factor authentication processcomprises: injecting a user interface interference to an interfacepresented to said user; and receiving from said user said correct valuein an input manner which reacts to said interference and which exhibitsa particular user-specific trait that had been extracted from previousinput-unit interactions of said user in response to said interference.13. The method of claim 1, further comprising: presenting to the user,one interference at a time, a sequence of user-interface interferencesthat are selected one at a time from a pool of possible user-interfaceinterferences; monitoring user reactions to the user-interfaceinterferences that were presented to the user, one interference at atime; generating a user-specific general reaction model that reflects ageneral manner of reactions to user-interface interferences by saiduser; generating an encryption key by using a parameter of saiduser-specific general reaction model; encrypting a content item of saiduser by using said encryption key that was generated based on saiduser-specific general reaction model.
 14. The method of claim 13,further comprising: upon a user request to decrypt said content item,performing: presenting to the user a single user-interface interference,from the sequence of user-interface interferences that were selected andused for generating the user-specific general reaction model prior tosaid encrypting step; monitoring a current reaction of said user to thesingle user-interface interference that is presented to the user;extracting a user-specific value from the current reaction of said userto the single user-interface interference that is presented to the user;calculating a decryption key based on the user-specific value that wasextracted from the current reaction of said user to the singleuser-interface interference that is presented to the user; decryptingsaid content item by using said decryption key.
 15. The method of claim13, wherein said sequence of user-interface interference comprise asequence of at least 20 user-interface interferences, that are selectedone-at-a-time from a pool comprising at least 100 user-interfaceinterferences.
 16. The method of claim 1, further comprising: performingstochastic encryption of a content item associated with said user, byutilizing an encryption key that is based, at least partially, on auser-specific model that reflects a general manner in which said userresponds to at least 10 different user-interface interferences.
 17. Themethod of claim 1, further comprising: performing stochastic encryptionof a content item associated with said user, by utilizing an encryptionkey that is based, at least partially, on a user-specific model thatreflects a general manner in which said user responds to a series of atleast 10 different user-interface interferences that were presented tosaid user one interference at a time; performing stochastic decryptionof said content item associated with said user, by utilizing adecryption key that is based, at least partially, on a single reactionof said user to a single user-interface interference that is presentedto said user in response to a user request to decrypt said content item.18. The method of claim 1, further comprising: performing a stochasticcryptography operation which utilizes, as a cryptographic parameter, avalue of a user-specific model of reaction to a user interfaceinterference of a particular type.
 19. The method of claim 1, furthercomprising: injecting a user interface interference to an interaction ofsaid user with said computerized service; monitoring user reaction tosaid user interface interference; extracting a user-specificinterference-specific parameter which indicates an attribute of the userreaction to said user interface interference; performing a stochasticcryptography operation which utilizes, as a cryptographic parameter, avalue of said user-specific interference-specific parameter whichindicates said attribute of the user reaction to said user interfaceinterference.
 20. The method of claim 19, comprising: estimating a falsepositive margin-of-error of said stochastic cryptography operation;allowing the user to perform multiple access attempts to compensate forthe estimated false positive margin-of-error of said stochasticcryptography operation.
 21. The method of claim 19, wherein thestochastic cryptography operation comprises at least one of: encryption,decryption.
 22. The method of claim 19, wherein the cryptographicparameter comprises: a value of said user-specific interference-specificparameter which indicates said attribute of the user reaction to saiduser interface interference which is introduced during said visual loginprocess.
 23. A system comprising: a visual login module to differentiatebetween a first user and a second user of a computerized service,wherein the visual login module is: to present an on-screen visual logininterface which requires a user of the computerized service to interactwith user interface elements in order to enter user login credentialsfor said computerized service; to monitor interactions of said used viaan input unit with said user interface elements of said on-screen visuallogin interface; to extract from said interaction of the user via theinput unit, a user-specific trait indicating a user-specific manner ofinteraction with said on-screen visual login interface; based on theextracted user-specific manner of interaction, to differentiate betweena first user and a second user of said computerized service; wherein thevisual login module is to present an on-screen vault interface havingone or more on-screen cylinders, and to generate an on-screen interfacethat allows the user to selectively rotate the one or more on-screenrotatable cylinders in order to input a Personal Identification Number(PIN) that the user desires to enter; wherein the visual login module isto monitor a manner in which the user performs rotations of the one ormore on-screen rotatable cylinders, and to extract a user-specific traitfrom said rotations.
 24. The system of claim 23, wherein the visuallogin module is to perform an implicit two-factor authentication processas a condition for authorizing said user to access said computerizeddevice, wherein a first-step of the implicit two-factor authenticationprocess comprises receiving from the user a correct value of a passwordpreviously-defined by said user; wherein a second-step of the implicittwo-factor authentication process comprises receiving from said usersaid correct value in an input manner that exhibits a particularuser-specific trait that had been extracted from previous input-unitinteractions of said user.
 25. The system of claim 23, furthercomprising a stochastic cryptography module, wherein the stochasticcryptography module is: to inject a user interface interference to aninteraction of said user with said computerized service; to monitor userreaction to said user interface interference; to extract a user-specificinterference-specific parameter which indicates an attribute of the userreaction to said user interface interference; to perform a stochasticcryptography operation which utilizes, as a cryptographic parameter, avalue of said user-specific interference-specific parameter whichindicates said attribute of the user reaction to said user interfaceinterference.